ORCID Profile
0000-0002-6825-5777
Current Organisation
Monash University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Synthesis of Materials | Industrial Chemistry | Organic Chemistry | Catalysis and Mechanisms of Reactions | Macromolecular and Materials Chemistry | Biomaterials | Organic Green Chemistry | Organic Chemical Synthesis | Polymers and Plastics | Physical Chemistry (Incl. Structural) | Bioprocessing, Bioproduction and Bioproducts |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Chemical Sciences | Management of Solid Waste from Plant Production | Plastic Products (incl. Construction Materials) | Industrial Chemicals and Related Products not elsewhere classified | Inorganic Industrial Chemicals | Organic Industrial Chemicals (excl. Resins, Rubber and Plastics) | Expanding Knowledge in Technology
Related Links
Publications
Mechanism of poly(methyl methacrylate) film formation by pulsed laser deposition
Publisher: AIP Publishing
Date: 07-2006
DOI: 10.1063/1.2209434
Abstract: The formation of poly(methyl methacrylate) films during pulsed laser deposition was studied by deposition at different substrate temperatures and by using targets with defined molecular mass and tacticity. At room temperature, the films (deposited from high-molecular weight polymer targets) mainly consist of macromolecules with average molecular masses of about 8000g∕mol. Up to substrate temperatures of 100°C, this average mass remains constant, suggesting the transport of larger polymeric fragments from the target to the substrate surface. This hypothesis is also confirmed by experiments using target material of lower molecular weight and of defined tacticity. At temperatures above 100°C and thus at conditions of enhanced mobility, the substrate molecular weight increases with temperature. The experiments indicate that the films are formed by deposition and reaction of macromolecular species. Radical polymerization of monomers described in the literature as a dominating film formation process plays no significant role.
Precise Polymer Synthesis by Autonomous Self‐Optimizing Flow Reactors
Publisher: Wiley
Date: 21-11-2018
Abstract: A novel continuous flow system for automated high-throughput screening, autonomous optimization, and enhanced process control of polymerizations was developed. The computer-controlled platform comprises a flow reactor coupled to size exclusion chromatography (SEC). Molecular weight distributions are measured online and used by a machine-learning algorithm to self-optimize reactions towards a programmed molecular weight by dynamically varying reaction parameters (i.e. residence time, monomer concentration, and control agent/initiator concentration). The autonomous platform allows targeting of molecular weights in a reproducible manner with unprecedented accuracy (<2.5 % deviation from pre-selected goal) for both thermal and light-induced reactions. For the first time, polymers with predefined molecular weights can be custom made under optimal reaction conditions in an automated, high-throughput flow synthesis approach with outstanding reproducibility.
Propagation rate coefficients of isobornyl acrylate, tert‐butyl acrylate and 1‐ethoxyethyl acrylate: A high frequency PLP‐SEC study
Publisher: Wiley
Date: 27-10-2009
DOI: 10.1002/POLA.23706
Abstract: Pulsed laser polymerization (PLP) coupled to size exclusion chromatography (SEC) is considered to be the most accurate and reliable technique for the determination of absolute propagation rate coefficients, k p . Herein, k p data as a function of temperature were determined via PLP‐SEC for three acrylate monomers that are of particular synthetic interest (e.g., for the generation of hiphilic block copolymers). The high‐ T g monomer isobornyl acrylate ( i BoA) as well as the precursor monomers for the synthesis of hydrophilic poly(acrylic acid), tert ‐butyl acrylate ( t BuA), and 1‐ethoxyethyl acrylate (EEA) were investigated with respect to their propagation rate coefficient in a wide temperature range. By application of a 500 Hz laser repetition rate, data could be obtained up to a temperature of 80 °C. To arrive at absolute values for k p , the Mark‐Houwink parameters of the polymers have been determined via on‐line light scattering and viscosimetry measurements. These read: K = 5.00 × 10 5 dL g −1 , a = 0.75 (p i BoA), K = 19.7 × 10 5 dL g −1 , a = 0.66 (p t BA) and K = 1.53 × 10 5 dL g −1 , a = 0.85 (pEEA). The bulky i BoA monomer shows the lowest propagation rate coefficient among the three monomers, while EEA is the fastest. The activation energies and Arrhenius factors read: ( i BoA): log( A /L mol −1 s −1 ) = 7.05 and E A = 17.0 kJ mol −1 ( t BuA): log( A /L mol −1 s −1 ) = 7.28 and E A = 17.5 kJ mol −1 and (EEA): log( A /L mol −1 s −1 ) = 6.80 and E A = 13.8 kJ mol −1 . © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6641–6654, 2009
Quasi-monodisperse polymer libraries via flash column chromatography: correlating dispersity with glass transition
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8PY01603H
Abstract: Quasi-monodisperse ( Đ = 1.005–1.040) poly(methyl) acrylate (PMA) polymer libraries are obtained via flash column chromatography separation of disperse ( Đ = 1.130) PMA. The influence of dispersity on the glass transition is investigated.
Versatile Approach for the Synthesis of Sequence-Defined Monodisperse 18- and 20-mer Oligoacrylates
Publisher: American Chemical Society (ACS)
Date: 24-06-2017
Direct synthesis of acrylate monomers in heterogeneous continuous flow processes
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7RE00120G
Abstract: An efficient, safe and convenient laboratory scale continuous flow process for synthesis of (meth)acrylate monomers is described.
Acid-Induced Room Temperature RAFT Polymerization: Synthesis and Mechanistic Insights
Publisher: American Chemical Society (ACS)
Date: 20-05-2016
Deconstructing Oligomer Distributions: Discrete Species and Artificial Distributions
Publisher: Wiley
Date: 27-08-2019
Abstract: The separation of an oligo(methyl acrylate) distribution, obtained from reversible addition-fragmentation chain transfer (RAFT) polymerization, in a discrete (dispersity=1) oligomeric library (degree of polymerization between 1 and 22) is presented. The properties of this library in terms of diffusivity, glass transition temperature, and viscosity are determined, filling a significant knowledge gap associated with these materials. The obtained oligomer library is used to construct artificial oligomer distributions on demand. These artificial oligomer distributions are used to highlight the potential to tailor physical properties of a material, while concomitantly demonstrating the limitations associated with size-exclusion chromatography analysis of molecular weight and dispersity in particular.
[2+2] Photo-cycloadditions for polymer modification and surface decoration
Publisher: Elsevier BV
Date: 2015
Synthesis of sequence controlled acrylate oligomers via consecutive RAFT monomer additions
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC45994B
Abstract: Two sets of sequence controlled oligoacrylates with four monomer insertions are synthesized via the RAFT technique and purified with automated recycling GPC. The insertion and order of monomers can be effectively controlled.
Critically Evaluated Rate Coefficients in Radical Polymerization – 8. Propagation Rate Coefficients for Vinyl Acetate in Bulk
Publisher: Wiley
Date: 26-09-2016
Amino acid acrylamide mimics: creation of a consistent monomer library and characterization of their polymerization behaviour
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1PY00735A
Abstract: A novel consistent approach to mimic the structure of biopolymers via precision polymer synthesis with reversible deactivation radical polymerization (RDRP).
Improved Livingness and Control over Branching in RAFT Polymerization of Acrylates: Could Microflow Synthesis Make the Difference?
Publisher: Wiley
Date: 24-09-2015
Abstract: The superior capabilities of structured microreactors over batch reactors are demonstrated for reversible addition-fragmentation chain transfer (RAFT) solution polymerization of n-butyl acrylate with the aid of simulations, explicitly accounting for the chain length distribution of all macrospecies types. Since perfect isothermicity can be established in a microreactor, less side products due to backbiting and β-scission are formed compared to the batch operation in which ineffective heat removal leads to an undesirable temperature spike. For a given RAFT chain transfer agent (CTA), additional microstructural control results under microflow conditions by optimizing the reaction temperature, lowering the dilution degree, or decreasing the initial molar ratio of monomer to RAFT CTA.
Chain Length Dependent Termination in Butyl Acrylate Free-Radical Polymerization Studied via Stationary and Pulsed Laser Initiated RAFT Polymerization
Publisher: American Chemical Society (ACS)
Date: 21-10-2005
DOI: 10.1021/MA051485K
Detailed investigation of the propagation rate of urethane acrylates
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B9PY00352E
Abstract: Propagation rate coefficients are provided—for the first time—for an entire class of urethane moieties containing acrylates, which display an extremely high propagation rate.
UV-induced functionalization of poly(divinylbenzene) nanoparticlesvia efficient [2 + 2]-photocycloadditions
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3PY00427A
Abstract: A facile postmodification strategy for the surface functionalization of nanoparticles is presented based on [2 + 2] photoconjugation with particles made from miniemulsion polymerization of inylbenzene.
Determination of Addition and Fragmentation Rate Coefficients in RAFT Polymerization via Time‐Resolved ESR Spectroscopy after Laser Pulse Initiation
Publisher: Wiley
Date: 30-01-2006
Improved Mechanistic Insights into Radical Sulfinyl Precursor MDMO-PPV Synthesis by Combining Microflow Technology and Computer Simulations
Publisher: American Chemical Society (ACS)
Date: 02-11-2015
Studying the Mechanism of Thioketone-Mediated Polymerization via Electrospray Ionization Mass Spectrometry
Publisher: Wiley
Date: 25-02-2009
DOI: 10.1002/POLA.23280
Abstract: The polymeric product spectrum generated in thioketone‐mediated free radical polymerization (TKMP) was analyzed via electrospray ionization mass spectrometry. Poly( n ‐butyl acrylate) s les were synthesized in the presence of the (commercially available) thioketone 4,4‐bis(dimethylamino)thiobenzophenone under variable reaction conditions in toluene solution at 80 °C. To unambiguously assign the mass spectra, the s les are prepared under variation of the monomer (going from n ‐butyl acrylate to ethyl acrylate) as well as by employing variable thermally decomposing initiators [i.e., 2,2′‐azoisobutyronitrile and azobis(cyclohexanecarbonitrile)]. In all mass spectra, significant amounts of the expected cross‐termination product, formed via bimolecular termination of propagating macroradicals with the dormant thioketone radical adduct (consisting of a propagating chain and the mediating thioketone) alongside conventional termination products can be identified. As the study was carried out on acrylate polymers, acrylate‐specific reaction products arising from intramolecular transfer reactions followed by β‐scission of the generated mid‐chain radicals are also identified in the mass spectra. In addition, a species congruent with the dormant thioketone radical adduct itself (oxidized to its cationic state) was identified. Products that could potentially be formed via a chain transfer mechanism cannot be identified. The results presented here thus support the earlier suggested TKMP mechanism involving a highly stabilized adduct radical which undergoes significant cross‐termination reactions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1864–1876, 2009
Tailoring Polymer Dispersity by RAFT Polymerization: A Versatile Approach
Publisher: Elsevier BV
Date: 06-2020
A predictive framework for mixing low dispersity polymer samples to design custom molecular weight distributions
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY01012B
Abstract: Predicting the shape and properties of artificial molecular weight distributions from mixing in idual polymer distributions.
Spin capturing with Clickable nitrones: Generation of miktoarmed star polymers
Publisher: American Chemical Society (ACS)
Date: 16-03-2010
DOI: 10.1021/MA100263K
High Throughput Multidimensional Kinetic Screening in Continuous Flow Reactors
Publisher: Wiley
Date: 16-08-2023
Abstract: An automated high throughput multidimensional reaction screening platform based on an inline Fourier‐transform infrared spectroscopy is presented. By combining flow chemistry, machine automation and inline analysis, the platform is able to screen reactions in multidimensions (residence time, monomer concentration, degree of polymerization, reaction temperature and monomer conversion) rapidly and efficiently way. Kinetic data libraries associated with high data precision (absolute error %), high reproducibility and high data density are built with ease from the platform. To test the method, we screened the reversible addition‐fragmentation chain transfer polymerization of methyl acrylate in unmatched detail, and the ring opening metathesis polymerization of methyl‐5‐norbornene‐2‐carboxylate. The method we introduce is a key step in providing “big data” for data driven research in the future, and already at present allows for precise prediction of reaction outcomes within the high‐dimensional chemical parameter space that is screened.
Combustion deposition of MoO3 films: from fundamentals to OPV applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA18001E
Abstract: Strong indications for combustion in films illustrated by morphological properties of the functional MoO 3 layers.
Efficiency assessment of single unit monomer insertion reactions for monomer sequence control: kinetic simulations and experimental observations
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5PY00485C
Abstract: On-line microreactor/ESI-MS experiments and kinetic simulations on single unit monomer insertions are combined to assess the efficiency of the SUMI process.
Efficient [2+2] photocycloadditions under equimolar conditions by employing a continuous UV-flow reactor
Publisher: Elsevier BV
Date: 05-2013
Synthesis of Macromonomers from High-Temperature Activation of Nitroxide Mediated Polymerization (NMP)-made Polyacrylates
Publisher: American Chemical Society (ACS)
Date: 24-04-2013
DOI: 10.1021/MA400477T
Laser induced marking of polymer chains with radical spin traps
Publisher: Wiley
Date: 19-03-2008
Laser-Grafted Molecularly Imprinted Polymers for the Detection of Histamine from Organocatalyzed Atom Transfer Radical Polymerization
Publisher: American Chemical Society (ACS)
Date: 11-03-2019
Photo-induced copper-mediated acrylate polymerization in continuous-flow reactors
Publisher: Springer Science and Business Media LLC
Date: 09-2016
Tuning of cross-linking and mechanical properties of laser-deposited poly (methyl methacrylate) films
Publisher: AIP Publishing
Date: 03-2005
DOI: 10.1063/1.1850609
Abstract: The chemical composition, amount of cross-linking and its influence on the mechanical properties of poly(methyl methacrylate) (PMMA) thin films produced by pulsed laser deposition (PLD) at a wavelength of 248nm under ultrahigh vacuum were investigated by infrared spectroscopy, scanning electron microscopy, size-exclusion chromatography, thermogravimetric analysis, and nanoindentation experiments. The films consist of two components, one fraction with a molecular weight well below that of the target material and a second fraction, which is cross-linked. Compared to bulk material, the Young’s modulus of the film is increased. The amount of cross-linking in the film can be tuned by the applied laser fluence leading to changes of the mechanical properties.
Continuous photoflow synthesis of precision polymers
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5RE00042D
Abstract: Precision polymer design in continuous photoflow reactors is a young, yet rapidly growing research field. The potential of photopolymerization is demonstrated and future potential is discussed.
The effects of molecular weight dispersity on block copolymer self-assembly
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2PY00318J
Abstract: The influence of dispersity in the molecular weight distributions in the core forming block for block copolymer (BCP) self-assembly is analyzed via an automated flow synthesis approach.
Concurrent control over sequence and dispersity in multiblock copolymers
Publisher: Springer Science and Business Media LLC
Date: 29-11-2021
DOI: 10.1038/S41557-021-00818-8
Abstract: Controlling monomer sequence and dispersity in synthetic macromolecules is a major goal in polymer science as both parameters determine materials' properties and functions. However, synthetic approaches that can simultaneously control both sequence and dispersity remain experimentally unattainable. Here we report a simple, one pot and rapid synthesis of sequence-controlled multiblocks with on-demand control over dispersity while maintaining a high livingness, and good agreement between theoretical and experimental molecular weights and quantitative yields. Key to our approach is the regulation in the activity of the chain transfer agent during a controlled radical polymerization that enables the preparation of multiblocks with gradually ascending (Ɖ = 1.16 → 1.60), descending (Ɖ = 1.66 → 1.22), alternating low and high dispersity values (Ɖ = 1.17 → 1.61 → 1.24 → 1.70 → 1.26) or any combination thereof. We further demonstrate the potential of our methodology through the synthesis of highly ordered pentablock, octablock and decablock copolymers, which yield multiblocks with concurrent control over both sequence and dispersity.
Modifiable poly(p-phenylene vinylene) copolymers towards functional conjugated materials
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY00688D
Abstract: The copolymerization of poly[2-methoxy-5-(3,7-dimethyloctyloxy)- p -phenylene vinylene] (MDMO-PPV) with poly[2-methoxy-5-(carboxypentyloxy)-PPV] (CPM-PPV) and poly[2,5-dicyano-PPV] (CN-PPV) is studied and postpolymerization modification with water soluble substituents is demonstrated.
Termination Kinetics of Dibutyl Itaconate Free‐Radical Polymerization Studied via the SP–PLP–ESR Technique
Publisher: Wiley
Date: 19-01-2005
Photoresponsive Emulsion-Templated Porous Materials via Orthogonal Photoclick Chemistry
Publisher: American Chemical Society (ACS)
Date: 17-02-2023
Controlling the Fate of Midchain Radicals in Acrylate Polymerization
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/CH08198
Solvent-Independent Molecular Weight Determination of Polymers Based on a Truly Universal Calibration
Publisher: Wiley
Date: 14-12-2022
Abstract: Diffusion‐ordered NMR spectroscopy (DOSY) allows for accurate molecular weight calibration and determination that can be corrected for solvent influences. Polystyrene and poly(ethylene glycol) standards have been used to calibrate DOSY diffusion data for a variety of solvents, showing a high correlation of data when the bulk viscosity of the solvent is accounted for following the Stokes–Einstein equation. In this way, a type of universal calibration is introduced that allows for determinations of average molecular weight that are at least as accurate as those of traditional size‐exclusion chromatography (SEC), if not better. Further, we demonstrate that DOSY calibrations can be used between laboratories, hence removing the need for in idual calibration of setups as currently done.
Mapping Dithiobenzoate-Mediated RAFT Polymerization Products via Online Microreactor/Mass Spectrometry Monitoring
Publisher: MDPI AG
Date: 06-11-2018
Abstract: 2-cyano-2-propyl dithiobenzoates (CPDB)-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization was monitored by online flow microreactor/mass spectrometry. This enabled the reactions to be followed in a time-resolved manner, closely resolving product patterns in the reaction mixtures at any point in time. RAFT polymerization was investigated for low RAFT to monomer ratios, enabling the monitoring of the early stages of a typical RAFT polymerization. The expected transition from pre- to the RAFT main equilibrium is observed. However, very high abundancies for cross-termination products were also identified, both in the pre- and main equilibrium stage. This is a somewhat surprising result as such products have always been expected, but to date have not been observed in the majority of studies. Product isolation and NMR analysis revealed that cross-termination occurs in the para position of the benzoate ring and becomes fully irreversible via re-aromatization of the ring in a H-shift reaction. The present data suggest a pronounced chain-length dependence of the cross-termination reaction, which would explain why the products are seen here, but not in other studies.
Scalable Synthesis of Sequence‐Defined Oligomers via Photoflow Chemistry
Publisher: Wiley
Date: 20-02-2019
Synthesis of star and H-shape polymers via a combination of cobalt-mediated radical polymerization and nitrone-mediated radical coupling reactions
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1PY00297J
Abstract: Via the combination of nitrone-mediated radical coupling and cobalt-mediated radical polymerization, mid-chain functionalized polymers are obtained that can be assembled into H-shaped polymers.
Efficient multiblock star polymer synthesis from photo-induced copper-mediated polymerization with up to 21 arms
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY00175K
Abstract: Photo-induced copper-mediated polymerization (photoCMP) is employed for the synthesis of multiarm-multiblock star copolymers. Based on a core-first approach, star polymers with four, six and twenty-one arms have been synthesized.
Cross-linked degradable poly(β-thioester) networks via amine-catalyzed thiol-ene click polymerization
Publisher: Elsevier BV
Date: 08-2014
Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization
Publisher: Elsevier BV
Date: 07-2012
Thermal detection of histamine with a graphene oxide based molecularly imprinted polymer platform prepared by reversible addition–fragmentation chain transfer polymerization
Publisher: Elsevier BV
Date: 11-2014
Elucidation of the properties of discrete oligo(meth)acrylates
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY01494B
Abstract: Discrete (monodisperse) methyl methacrylate (MMA) and di(ethylene glycol) ethyl ether acrylate (DEGEEA) oligomer libraries are generated via a 2-step process of RAFT polymerization and chromatographic separation.
Mark-Houwink Parameters for the Universal Calibration of Acrylate, Methacrylate and Vinyl Acetate Polymers Determined by Online Size-Exclusion Chromatography-Mass Spectrometry
Publisher: Wiley
Date: 26-02-2010
Kinetic Control of Aggregation Shape in Micellar Self-Assembly
Publisher: Wiley
Date: 19-08-2019
Abstract: The first steps towards top-down morphology control in micellar self-assembly are introduced. Kinetically stable micelles are formed from block copolymers (BCPs) using continuous flow techniques by turbulent mixing of water with a THF solution of polymers. In this way, particle shape and size can be altered from spheres to ellipsoids solely via tuning of mixing parameters from a single BCP.
Free-radical propagation and termination kinetics of the butyl acrylate dimer studied by pulsed laser polymerization techniques
Publisher: Elsevier BV
Date: 07-2009
Particle Size Control in Miniemulsion Polymerization via Membrane Emulsification
Publisher: American Chemical Society (ACS)
Date: 12-06-2019
Formation efficiency of ABA blockcopolymers via enhanced spin capturing polymerization (ESCP): Locating the alkoxyamine function
Publisher: American Chemical Society (ACS)
Date: 02-07-2009
DOI: 10.1021/MA900356P
Advanced polymer flow synthesis
Publisher: Elsevier BV
Date: 07-2016
UV‐Induced [2+2] Grafting‐To Reactions for Polymer Modification of Cellulose
Publisher: Wiley
Date: 02-11-2015
Abstract: Benzaldehyde‐functional cellulose paper sheets have been synthesized via tosylation of cellulose (Whatman No 5) followed by addition of p ‐hydroxy benzaldehyde. Via UV‐induced Paterno–Büchi [2+2] cycloaddition reactions, these aldehyde functional surfaces are grafted with triallylcyanurate, trimethylolpropane allyl ether, and vinyl chloroacetate. In the following, allyl‐functional polymers (poly(butyl acrylate), pBA, M n = 6990 g mol −1 , Đ = 1.12 and poly( N ‐isopropyl acrylamide), pNIPAAm, M n = 9500 g mol −1 , Đ = 1.16) synthesized via reversible addition fragmentation chain transfer polymerization are conjugated to the celloluse surface in a UV‐induced grafting‐to approach. With pBA, hydrophobic cellulose sheets are obtained (water contact angle 116°), while grafting of pNIPAAm allows for generation of “smart” surfaces, which are hydrophilic at room temperature, but that become hydrophobic when heated above the characteristic lower critical solution temperature (93° contact angle). The Paterno–Büchi reaction has been shown to be a versatile synthetic tool that also performs well in grafting‐to approaches whereby its overall performance seems to be close to that of radical thiol‐ene reactions. image
Exploring the Photochemical Reactivity of Multifunctional Photocaged Dienes in Continuous Flow
Publisher: Wiley
Date: 14-08-2019
Tunable thermoresponsive β‐cyclodextrin‐based star polymers
Publisher: Wiley
Date: 23-11-2020
DOI: 10.1002/POL.20200634
Mapping Poly(butyl acrylate) Product Distributions by Mass Spectrometry in a Wide Temperature Range: Suppression of Midchain Radical Side Reactions
Publisher: American Chemical Society (ACS)
Date: 09-11-2007
DOI: 10.1021/MA071471+
Quantitative Comparison of the Mesitoyl vs the Benzoyl Fragment in Photoinitiation: A Question of Origin
Publisher: American Chemical Society (ACS)
Date: 30-03-2011
DOI: 10.1021/MA2001977
Controlled/living polymerization towards functional poly(p-phenylene vinylene) materials
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5PY01987G
Abstract: Poly( p -phenylene vinylene)s (PPVs) are an important class of highly fluorescent polymeric semiconductor materials.
Facile design of degradable poly(β‐thioester)s with tunable structure and functionality
Publisher: Wiley
Date: 06-11-2013
DOI: 10.1002/POLA.26986
Abstract: The synthesis of a range of linear biodegradable poly(β‐thioester)s, PBTs, via hexylamine‐catalyzed thiol‐ene Micheal additions between a variety of diacrylate and dithiol monomers is described. Molecular weights up to 12,000 g mol −1 are obtained for this new class of polymer materials. PBTs featuring very different chemical and mechanical behavior are obtained on the basis of seven diacrylate and three dithiol monomers. Polar PBTs are synthesized based on ethylene glycol‐containing monomers in an environmentally friendly solvent. Furthermore, PBTs containing urethane units in the main chain are obtained, providing access to an isocyanate‐free polyurethane polymerization method. The thiol‐ene addition approach can also be used to couple polystyrene oligomers synthesized from a bifunctional trithiocarbonate reversible addition fragmentation transfer agent. In this way, PBTs featuring polystyrene segments as well as diacrylate segments are produced. In general for these step‐growth polymerizations, by tuning the stoichiometric monomer ratio, a desired end group functionality can be quantitatively introduced into the PBT, which is demonstrated via soft ionization mass spectrometry analysis. As an ex le, alkyne end groups have been built in, giving access to use these materials in modular polymer design strategies. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 178–187
Reducing the Degree of Branching in Polyacrylates via Midchain Radical Patching: A Quantitative Melt-State NMR Study
Publisher: American Chemical Society (ACS)
Date: 11-06-2010
DOI: 10.1021/MA100991C
Anionic flow polymerizations toward functional polyphosphoesters in microreactors: Polymerization and UV-modification
Publisher: Elsevier BV
Date: 07-2016
Sequence-definition from controlled polymerization: the next generation of materials
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8PY01190G
Abstract: An overview is given on the state-of-the-art in synthesis of sequence-controlled and sequence-defined oligomers and polymers.
Continuous Synthesis and Thermal Elimination of Sulfinyl‐Route Poly(p‐Phenylene Vinylene) in Consecutive Flow Reactions
Publisher: Wiley
Date: 28-08-2015
Synthesis of degradable multi-segmented polymers via Michael-addition thiol–ene step-growth polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA18861J
Abstract: Degradable multi-segmented poly(β-thioester) linear polymers and networks are synthesized via step-growth thiol–ene polymerization of diacrylates with telechelic dithiol polystyrene and poly(isobornylacrylate) precursor polymers.
Thioketone‐Mediated Polymerization of Butyl Acrylate: Controlling Free‐Radical Polymerization via a Dormant Radical Species
Publisher: Wiley
Date: 16-03-2007
Thermally responsive core–shell microparticles and cross-linked networks based on nitrone chemistry
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2PY20272G
Abstract: Complex cross-linked soluble architectures are generated using nitrone mediated chemistry and are subsequently cleaved into network fragments. Nitrone mediated reactions are additionally applied for the synthesis of stimuli-responsive microspheres.
Continuous ATRP Synthesis of Block‐Like Copolymers via Column Reactors: Design and Validation of a Kinetic Model
Publisher: Wiley
Date: 21-11-2009
Improved photo-induced cobalt-mediated radical polymerization in continuous flow photoreactors
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5PY00299K
Abstract: The implementation of cobalt-mediated radical polymerization (CMRP) for continuous microflow reactor synthesis is described.
Online Monitoring of Polymerizations: Current Status
Publisher: Wiley
Date: 22-09-2017
Photoinduced Conjugation of Aldehyde Functional Polymers with Olefins via [2 + 2]-Cycloaddition
Publisher: American Chemical Society (ACS)
Date: 30-09-2011
DOI: 10.1021/MA2017748
Synthesis of poly(p-phenylene vinylene) materials via the precursor routes
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1PY00345C
Abstract: The precursor routes to obtain high-molecular weight poly(p-phenylene vinylene)s (PPVs) are reviewed with respect to their applicability towards specific synthesis goals and materials as well as their structural integrity.
Automated Polymer Synthesis Platform for Integrated Conversion Targeting Based on Inline Benchtop NMR
Publisher: American Chemical Society (ACS)
Date: 11-10-2019
A qualitative and quantitative post-mortem analysis: Studying free-radical initiation processes via soft ionization mass spectrometry
Publisher: Wiley
Date: 26-04-2012
DOI: 10.1002/POLA.26076
Abstract: The current article contains a review of the electrospray ionization‐mass spectrometry characterization of polymers prepared via thermal‐ and photoinitiation processes. The used analysis method permits direct access to detailed endgroup information. For a qualitative and quantitative endgroup analysis, sophisticated methods have been developed which provide a detailed image of the incorporation propensity of thermally as well as photolytically generated radicals at the polymer chain termini. Such a post‐mortem analysis of polymeric materials specifically allows for the quantification of the ability of radical fragments to initiate polymerization processes. Herein, the most recent progress in the field of mass spectrometric radical reactivity mapping is outlined and open questions as well as future directions are discussed. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Designing molecular weight distributions of arbitrary shape with selectable average molecular weight and dispersity
Publisher: Elsevier BV
Date: 07-2020
Use of a continuous-flow microreactor for thiol–ene functionalization of RAFT-derived poly(butyl acrylate)
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2PY20423A
Abstract: Aminolysis and thiol–ene end group modifications of functionalized RAFT-derived poly( n -butyl acrylate) polymers are executed within 20 minutes in a continuous-flow microreactor.
Termination Kinetics of tert‐Butyl Methacrylate and of n‐Butyl Methacrylate Free‐Radical Bulk Homopolymerizations
Publisher: Wiley
Date: 21-09-2006
Size-dependent properties of functional PPV-based conjugated polymer nanoparticles for bioimaging
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.COLSURFB.2018.05.055
Abstract: Conjugated polymer nanoparticle systems have gained significant momentum in the bioimaging field on account of their biocompatibility and outstanding spectroscopic properties. Recently, new control procedures have spawned custom-built functional poly(p-phenylene vinylene) (PPV). These facilitate the one-pot synthesis of semiconducting polymer NPs with incorporated surface functional groups, an essential feature for advanced biomedical applications. In this work, nanoparticles (NPs) of different sizes are synthesized consisting of the statistical copolymer CPM-co-MDMO-PPV with monomer units 2-(5'-methoxycarbonylpentyloxy)-5-methoxy-1,4-phenylenevinylene (CPM-PPV) and poly(2-methoxy-5-(3',7'-dimethoxyoctyloxy)-1,4-phenylenevinylene) (MDMO-PPV). To monitor potential implications of switching from a commonly used homopolymer to copolymer system, MDMO-PPV NPs were prepared as a control. The versatile combination of the miniemulsion and solvent evaporation method allowed for an easy adaptation of the NP size. Decreasing the diameter of functional PPV-based NPs up to 20 nm did not significantly affect their optical properties nor the biocompatibility of the bioimaging probe, as cell viability never dropped below 90%. The quantum yield and molar extinction coefficient remained stable at values of 1-2% and 10
Synthesis of electrically conducting nanocomposites via Pickering miniemulsion polymerization: Effect of graphene oxide functionalized with different capping agents
Publisher: Elsevier BV
Date: 09-2022
Living Polymerization via Anionic Initiation for the Synthesis of Well‐Defined PPV Materials
Publisher: Wiley
Date: 09-01-2012
Abstract: The anionic polymerization of PPV via the sulfinyl precursor route is further investigated. When LHMDS is employed as the base to form the actively propagating quinodimethane system and THF as the solvent, anionic polymerizations can be observed. With the use of tert- butyl-substituted anionic initiators, specific functional groups can be built in the polymer chain and the chain length can be efficiently controlled, which is demonstrated here for the first time. With introduction of branched side chains on the aromatic core, soluble conjugated PPV material can be obtained with molecular weights in the range of 5000-16,000 g mol(-1).
Synthesis of sequence-defined acrylate oligomers via photo-induced copper-mediated radical monomer insertions
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5SC02035B
Abstract: Photo-induced copper-mediated radical polymerization is used to synthesize monodisperse sequence defined acrylate oligomers via consecutive single unit monomer insertion reactions and intermediate purification of the compounds by column or preparative recycling size exclusion chromatography.
Accelerated Polypeptide Synthesis via N‐Carboxyanhydride Ring Opening Polymerization in Continuous Flow
Publisher: Wiley
Date: 20-07-2020
Visible Light-Mediated Polymerization-Induced Self-Assembly Using Continuous Flow Reactors
Publisher: American Chemical Society (ACS)
Date: 06-07-2018
Limitations of radical thiol‐ene reactions for polymer–polymer conjugation
Publisher: Wiley
Date: 08-03-2010
DOI: 10.1002/POLA.23933
Abstract: In this work, we report our findings on the use of radical thiol‐ene chemistry for polymer–polymer conjugation. The manuscript combines the results from the Preparative Macromolecular Chemistry group from the Karlsruhe Institute of Technology (KIT) and the Polymer Chemistry Research group from Ghent University (UGent), which allowed for an investigation over a very broad range of reaction conditions. In particular, thermal and UV initiation methods for the radical thiol‐ene process were compared. In the KIT group, the process was studied as a tool for the synthesis of star polymers by coupling multifunctional thiol core molecules with poly( n ‐butyl acrylate) macromonomers (MM), employing thermally decomposing initiators. The product purity and thus reaction efficiency was assessed via electrospray ionization mass spectrometry. Although the reactions with 10 or 5 equivalents of thiol with respect to macromonomer were successful, the coupling reaction with a one‐to‐one ratio of MM to thiol yielded only a fraction of the targeted product, besides a number of side products. A systematic parameter study such as a variation of the concentration and nature of the initiator and the influence of thiol‐to‐ene ratio was carried out. Further experiments with poly(styrene) and poly(isobornyl acrylate) containing a vinylic end group confirmed that thermal thiol‐ene conjugation is far from quantitative in terms of achieving macromolecular star formation. In parallel, the UGent group has been focusing on photo‐initiated thiol‐ene chemistry for the synthesis of functional polymers on one hand and block copolymers consisting of poly(styrene) (PS) and poly(vinyl acetate) (PVAc) on the other hand. Various functionalization reactions showed an overall efficient thiol‐ene process for conjugation reactions of polymers with low molecular weight compounds (∼90% coupling yield). However, while SEC and FT‐IR analysis of the conjugated PS‐PVAc products indicated qualitative evidence for a successful polymer–polymer conjugation, 1 H NMR and elemental analysis revealed a low conjugation efficiency of about 23% for a thiol‐to‐ene ratio equal to one. Blank reactions using typical thiol‐ene conditions indicated that bimolecular termination reactions occur as competitive side reactions explaining why a molecular weight increase is observed even though the thiol‐ene reaction was not successful. The extensive study of both research groups indicates that radical thiol‐ene chemistry should not be proposed as a straightforward conjugation tool for polymer–polymer conjugation reactions. Head‐to‐head coupling is a major reaction pathway, which interrupts the propagation cycle of the thiol‐ene process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1699–1713, 2010
Visible light-induced iniferter polymerization of methacrylates enhanced by continuous flow
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY01157A
Abstract: Visible-light induced photoiniferter polymerization in continuous flow reactors is very efficient in yielding low dispersity methacrylate block copolymers.
Photoinduced Sequence-Controlled Copper-Mediated Polymerization: Synthesis of Decablock Copolymers
Publisher: American Chemical Society (ACS)
Date: 14-07-2014
DOI: 10.1021/MZ5003867
Abstract: Photoinitiated copper-mediated radical polymerization offers an one-pot and time efficient method of preparing a decablock copolymer PMA-PtBA-PMA-PDEGA-PMA-PtBA-PMA-PDEGA-PnBA-PDEGA with an overall molecular weight of 8500 g·mol
Amphiphilic conjugated block copolymers as NIR-bioimaging probes
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2PY00258B
Abstract: A novel method for creating a semiconducting nanoparticles of the donor–acceptor conjugated polymer p(IDT-NDI) containing indacenodithienothiophene (IDT) and naphthalene diimide (NDI) units is presented.
Micelle Purification in Continuous Flow via Inline Dialysis
Publisher: American Chemical Society (ACS)
Date: 16-04-2021
Ligand switch in photoinduced copper-mediated polymerization: synthesis of methacrylate–acrylate block copolymers
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5PY00592B
Abstract: The use of photo-induced copper-mediated radical polymerization (photoCMP) to synthesize mixed acrylate/methacrylate (methyl acrylate, MA and methyl methacrylate, MMA) block copolymers is investigated.
Synthesis of degradable poly(methyl methacrylate) star polymers via RAFT copolymerization with cyclic ketene acetals
Publisher: Wiley
Date: 07-04-2014
DOI: 10.1002/POLA.27180
Abstract: Copolymerization of the cyclic ketene acetal 5,6‐benzo‐2‐methylene‐1,3‐dioxepane (BMDO) with methyl methacrylate (MMA) is studied with respect to its copolymerization parameters and the suitability to control BMDO/MMA copolymerizations via the reversible addition‐fragmentation chain transfer (RAFT) technique to obtain linear and 4‐arm star polymers. BMDO shows disparate copolymerization behavior with MMA and r 1 = 0.33 ± 0.06 and r 2 = 6.0 ± 0.8 have been determined for polymerization at 110 °C in anisole from fitting copolymer composition vs. comonomer feed data to the Lewis–Mayo equation. Copolymerization of the two monomers is successful in RAFT polymerization employing a trithiocarbonate control agent. As desired, polymers contain only little amount of polyester units stemming from BMDO units and preliminary degradation experiment show that the polymer degrades slowly, but steadily in aqueous 1 M NaOH dispersion. Within ten days, the polymers are broken down to low molecular weight segments from an initial molecular weight of M n = 6000 g mol −1 . Star (co)polymerization with an erythritol‐based tetra‐functional RAFT agent following the Z‐group approach proceeds efficiently and polymers with a number‐average molecular weight of 10,000 g mol −1 are readily obtained that degrade in similar manner as the linear copolymer counterparts. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 1633–1641
Continuous Microflow PhotoRAFT Polymerization
Publisher: American Chemical Society (ACS)
Date: 15-09-2016
Tailoring Polymer Dispersity by Controlled Radical Polymerization: A Versatile Approach
Publisher: American Chemical Society (ACS)
Date: 12-02-2020
DOI: 10.26434/CHEMRXIV.11836137.V1
Abstract: Dispersity ( Ɖ ) can significantly affect polymer properties and is a key parameter in materials design however, current methods do not allow for the comprehensive control of dispersity. They are limited in monomer scope, may require the use of flow-based systems and/or additional reagents ( e.g. termination agents or co-monomers), and are often accompanied by multimodal molecular weight distributions, low initiator efficiencies or poor end-group fidelity. Herein, we report a straightforward and versatile batch method based on reversible addition-fragmentation chain transfer (RAFT) polymerization which enables good control over Ɖ of a wide range of monomer classes, including acrylates, acrylamides, methacrylates and styrene. In addition, our methodology is compatible with more challenging monomers such as methacrylic acid, vinyl ketone and vinyl acetate. Control over Ɖ is achieved by mixing two RAFT agents with sufficiently different transfer activities in various ratios, affording polymers with monomodal molecular weight distributions over a broad dispersity range ( Ɖ ~ 1.09-2.10). Our findings were further supported by simulations through the use of deterministic kinetic modelling which was fully in line with our experimental data, further confirming the power of our methodology. The robustness of the concept is further demonstrated by the preparation of well-defined block copolymers via chain extension of all polymers regardless of the initial Ɖ .
Update and critical reanalysis of IUPAC benchmark propagation rate coefficient data
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2PY00147K
Abstract: The dataset used to generate IUPAC benchmark Arrhenius parameters for propagation rate coefficients in radical polymerization is extended and reanalyzed, taking into account systematic interlaboratory variation.
The RAFT Process as a Kinetic Tool: Accessing Fundamental Parameters of Free Radical Polymerization
Publisher: Wiley
Date: 23-01-2008
Synthesis of PPV-b-PEG block copolymers via CuAAC conjugation
Publisher: Elsevier BV
Date: 06-2014
Surface Grafting via Photo‐Induced Copper‐Mediated Radical Polymerization at Extremely Low Catalyst Concentrations
Publisher: Wiley
Date: 06-07-2015
Abstract: Surface-initiated photo-induced copper-mediated radical polymerization is employed to graft a wide range of polyacrylate brushes from silicon substrates at extremely low catalyst concentrations. This is the first time that the controlled nature of the reported process is demonstrated via block copolymer formation and re-initiation experiments. In addition to unmatched copper catalyst concentrations in the range of few ppb, film thicknesses up to almost 1 μm are achieved within only 1 h.
Solvent Effects on Acrylate k(p) in Organic Media?-A Systematic PLP-SEC Study
Publisher: Wiley
Date: 31-10-2014
Abstract: The Arrhenius parameters of the propagation rate coefficient, kp , are determined employing high-frequency pulsed laser polymerization-size exclusion chromatography (PLP-SEC) for the homologous series of five linear alkyl acrylates (i.e., methyl acrylate (MA), butyl acrylate (BA), dodecyl acrylate (DA), stearyl acrylate (SA), and behenyl acrylate (BeA)) in 1 m solution in butyl acetate (BuAc) as well as in toluene. The comparison of the obtained kp values with the literature known values for bulk demonstrates that no significant solvent influence neither in BuAc nor in toluene on the propagation reaction compared to bulk is detectable. Concomitantly, the kp values in toluene and in BuAc solution display a similar increase with increasing number of C-atoms in the ester side chain as was previously reported for the bulk systems. These findings are in clear contrast to earlier studies, which report a decrease of kp with increasing ester side chain length in toluene. The additional investigation of the longest and shortest ester side chain acrylate (i.e., BeA and MA) over the entire experimentally available concentration range at one temperature (i.e., 50 °C) does not reveal any general concentration dependence and all observed differences in the kp are within the experimental error.
Muconic acid esters as bio-based acrylate mimics
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY01313J
Abstract: Dialkyl muconates are synthesized from biobased muconic acid. These monomers are shown to be readily polymerized in radical polymerizations, and may serve as alternatives to classical acrylates.
Nitrones in synthetic polymer chemistry
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0PY00377H
Abstract: Very recently, the development of enhanced spin capturing polymerization (ESCP) and nitrone-mediated radical coupling (NMRC) reactions—based on nitrone chemistry—has opened up novel synthetic avenues in macromolecular engineering. The synthetic potential of nitrones in polymer chemistry is discussed herein.
Narrowing down chain length effects on the antibacterial action of guanylated oligomers
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3PY00203A
Abstract: Synthesis of discrete guanylated antimicrobial oligomers through reversible addition fragmentation chain transfer (RAFT) polymerization followed by flash chromatography is described.
Elements of RAFT Navigation
Publisher: American Chemical Society
Date: 2018
Nitrone‐Mediated Radical Coupling of Polymers Derived from Reverse Iodine‐Transfer Polymerization
Publisher: Wiley
Date: 20-02-2014
Process intensification of continuous-flow seATRP by a sonicated multi-reactor setup
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3RE00235G
Abstract: A sonicated electrochemical multi-reactor setup is demonstrated for continuous-flow seATRP.
Enhanced Spin Capturing Polymerization of Ethylene
Publisher: American Chemical Society (ACS)
Date: 05-10-2012
DOI: 10.1021/MA3014806
Influence of dielectric layer thickness and roughness on topographic effects in magnetic force microscopy
Publisher: Beilstein Institut
Date: 17-05-2019
Abstract: Magnetic force microscopy (MFM) has become a widely used tool for the characterization of magnetic properties. However, the magnetic signal can be overlapped by additional forces acting on the tip such as electrostatic forces. In this work the possibility to reduce capacitive coupling effects between tip and substrate is discussed in relation to the thickness of a dielectric layer introduced in the system. Single superparamagnetic iron oxide nanoparticles (SPIONs) are used as a model system, because their magnetic signal is contrariwise to the signal due to capacitive coupling so that it is possible to distinguish between magnetic and electric force contributions. Introducing a dielectric layer between substrate and nanoparticle the capacitive coupling can be tuned and minimized for thick layers. Using the theory of capacitive coupling and the magnetic point dipole–dipole model we could theoretically explain and experimentally prove the phase signal for single superparamagnetic nanoparticles as a function of the layer thickness of the dielectric layer. Tuning the capacitive coupling by variation of the dielectric layer thickness between nanoparticle and substrate allows the distinction between the electric and the magnetic contributions to the MFM signal. The theory also predicts decreasing topographic effects in MFM signals due to surface roughness of dielectric films with increasing film thickness.
Photo-induced copper-mediated (meth)acrylate polymerization towards graphene oxide and reduced graphene oxide modification
Publisher: Elsevier BV
Date: 07-2020
Enhanced spin capturing polymerization: An efficient and versatile protocol for controlling molecular weight distributions
Publisher: Wiley
Date: 26-09-2008
DOI: 10.1002/POLA.23025
Muconic Acid Esters as Bio-Based Acrylate Mimics
Publisher: American Chemical Society (ACS)
Date: 14-08-2019
DOI: 10.26434/CHEMRXIV.9611909.V1
Abstract: The synthesis of polymers from radical polymerization of dialkyl muconates, a renewable monomer that is readily available from biofermentation, is described. Polymuconates are scarcly described in literature, and were previously believed to polymerize only sluggishly. In here we demonstrate the optimized polymerization that yields materials that are analoguous to classical oil-based polyacrylates. Thermal properties of the polymers are explored, and the abaility to control the polymerization via reversible deactivation radical polymerization is showcased.
Watching polymers grow: real time monitoring of polymerizations via an on-line ESI-MS/microreactor coupling
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CC10426A
Abstract: A microreactor/electrospray ionization MS coupling is introduced that allows us to observe and optimize polymerization reactions with respect to chain length and endgroup patterns in real time under synthesis conditions, which was not possible before.
Photomediated controlled radical polymerization
Publisher: Elsevier BV
Date: 11-2016
Operator-independent high-throughput polymerization screening based on automated inline NMR and online SEC
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2DD00035K
Abstract: Automated continuous flow is used as high-throughput method with high accuracy.
Chain-Length-Dependent Termination in Acrylate Radical Polymerization Studied via Pulsed-Laser-Initiated RAFT Polymerization
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/CH07236
Abstract: The chain-length dependence of the termination rate coefficient, kt, in methyl acrylate (MA) and dodecyl acrylate (DA) radical polymerization has been determined via the single pulse pulsed-laser polymerization near-infrared reversible addition–fragmentation chain transfer (SP-PLP-NIR-RAFT) technique. Polymerization is induced by a laser SP and the resulting decay in monomer concentration, cM, is monitored via NIR spectroscopy with a time resolution of microseconds. A RAFT agent ensures the correlation of radical chain length and monomer-to-polymer conversion. The obtained rate coefficients for termination of two radicals of approximately the same chain length, i, are represented by power-law expressions, kt(i,i) ∝ i–α. For both monomers, composite model behaviour of kt(i,i) showing two distinct chain length regimes is observed. The exponent αs referring to short chain lengths is close to unity, whereas the exponent αl, which characterizes the chain-length dependency of large radicals, is slightly above the theoretical value for coiled chain-end radicals. The crossover chain length, ic, which separates the two regions, decreases from MA (ic = 30) to DA (ic = 20). The results for MA and DA are consistent with earlier data reported for butyl acrylate. There appears to be a correlation of αs and ic with chain flexibility.
Kinetic Monte Carlo Generation of Complete Electron Spray Ionization Mass Spectra for Acrylate Macromonomer Synthesis
Publisher: American Chemical Society (ACS)
Date: 23-03-2017
Sequence‐Encoded
RAFT
Oligomers and Polymers
Publisher: Wiley
Date: 29-10-2021
Photoinduced Acrylate Polymerization: Unexpected Reduction in Chain Branching
Publisher: Wiley
Date: 06-2015
Abstract: The branching stemming from midchain radical formation in n-butyl acrylate polymerization is investigated via melt-state (13) C NMR measurements. The dependence of the degree of branching (DB) on the monomer conversion of the system is examined for photoinduced polymerizations, revealing a steady increase in branching with conversion. For polymerization at moderate light intensities, an increase in branching from 0.03% to 0.37% is observed for polymerizations at 60 °C, which is fivefold below the level of branching observed in thermally initiated polymerizations under otherwise identical reaction conditions. The reason for this overall reduction in branching remains momentarily unclear yet, a strong dependence of branching on light intensity is observed. While polymerization under a 1 W LED l results at almost full monomer conversion in branching degrees of 0.22%, polymerization under a 400 W l yields 1.81% of chain branches.
Polymer end group modifications and polymer conjugations via “click” chemistry employing microreactor technology
Publisher: Wiley
Date: 06-02-2014
DOI: 10.1002/POLA.27112
Abstract: This study presents the development of microreactor protocols for the successful continuous flow end group modification of atom transfer radical polymerization precursor polymers into azide end‐capped materials and the subsequent copper‐catalyzed azide alkyne click reactions with alkyne polymers, in flow. By using a microreactor, the reaction speed of the azidation of poly(butyl acrylate), poly(methyl acrylate), and polystyrene can be accelerated from hours to seconds and full end group conversion is obtained. Subsequently, copper‐catalyzed click reactions are executed in a flow reactor at 80 °C. Good coupling efficiencies are observed and various block copolymer combinations are prepared. Furthermore, the flow reaction can be carried out in only 40 min, while a batch procedure takes several hours to reach completion. The results indicate that the use of a continuous flow reactor for end group modifications as well as click reactions has clear benefits towards the development and improvement of well‐defined polymer materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 1263–1274
Alpha and Omega: Importance of the Nonliving Chain End in RAFT Multiblock Copolymerization
Publisher: American Chemical Society (ACS)
Date: 16-07-2014
DOI: 10.1021/MA500803K
Micro-patterned molecularly imprinted polymer structures on functionalized diamond-coated substrates for testosterone detection
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.BIOS.2018.07.032
Abstract: Molecularly imprinted polymers (MIPs) can selectively bind target molecules and can therefore be advantageously used as a low-cost and robust alternative to replace fragile and expensive natural receptors. Yet, one major challenge in using MIPs for sensor development is the lack of simple and cost-effective techniques that allow firm fixation as well as controllable and consistent receptor material distribution on the sensor substrate. In this work, a convenient method is presented wherein microfluidic systems in conjunction with in situ photo-polymerization on functionalized diamond substrates are used. This novel strategy is simple, efficient, low-cost and less time consuming. Moreover, the approach ensures a tunable and consistent MIP material amount and distribution between different sensor substrates and thus a controllable active sensing surface. The obtained patterned MIP structures are successfully tested as a selective sensor platform to detect physiological concentrations of the hormone disruptor testosterone in buffer, urine and saliva using electrochemical impedance spectroscopy. The highest added testosterone concentration (500 nM) in buffer resulted in an impedance signal of 10.03 ± 0.19% and the lowest concentration (0.5 nM) led to a measurable signal of 1.8 ± 0.15% for the MIPs. With a detection limit of 0.5 nM, the MIP signals exhibited good linearity between a 0.5 nM and 20 nM concentration range. Apart from the excellent and selective recognition offered by these MIP structures, they are also stable during and after the dynamic sensor measurements. Additionally, the MIPs can be easily regenerated by a simple washing procedure and are successfully tested for their reusability.
Macromol. Rapid Commun. 16/2015
Publisher: Wiley
Date: 08-2015
Controlled Reversible Deactivation Radical Photopolymerization
Publisher: The Royal Society of Chemistry
Date: 16-08-2018
DOI: 10.1039/9781788013307-00244
Abstract: Photoinduced reversible deactivation radical polymerization (photoRDRP) has in recent years become a popular method for the synthesis of precision polymer materials. PhotoRDRP often gives access to robust and energy-efficient polymerization methods, and allows for spatiotemporal control over reactions. For every major thermal RDRP technique, photoinduced counterparts are available, with photo-nitroxide mediated polymerization, photo-reversible addition–fragmentation chain transfer polymerization and photo-atom transfer radical polymerization. In this chapter, these techniques are summarized and compared, followed by an overview of 2D surface patterning based on photoRDRP and the application of continuous flow techniques for scalable photopolymerization.
Fast and Efficient [2 + 2] UV Cycloaddition for Polymer Modification via Flow Synthesis
Publisher: American Chemical Society (ACS)
Date: 12-08-2014
DOI: 10.1021/MA500751J
High-throughput polymer screening in microreactors: boosting the Passerini three component reaction
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY00360A
Abstract: The Passerini three-component reaction (Passerini-3CR) has been studied via on-line microreactor/electrospray ionisation mass spectrometry (MRT/ESI-MS) reaction monitoring to demonstrate the high-throughput screening potential of microreactors for macromolecular design.
Continuous poly(2-oxazoline) triblock copolymer synthesis in a microfluidic reactor cascade
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5CC04319K
Abstract: Continuous flow synthesis in coupled microreactors is used to synthesize poly(2-oxazoline) triblock copolymers with very high precision times, which are from classical batch synthesis almost not accessible. Also, reactions are speed up significantly leading to full synthesis in minutes rather than hours or days.
Reversible Surface Engineering via Nitrone-Mediated Radical Coupling
Publisher: American Chemical Society (ACS)
Date: 19-02-2018
DOI: 10.1021/ACS.LANGMUIR.7B03167
Abstract: Efficient and simple polymer conjugation reactions are critical for introducing functionalities on surfaces. For polymer surface grafting, postpolymerization modifications are often required, which can impose a significant synthetic hurdle. Here, we report two strategies that allow for reversible surface engineering via nitrone-mediated radical coupling (NMRC). Macroradicals stemming from the activation of polymers generated by copper-mediated radical polymerization are grafted via radical trapping with a surface-immobilized nitrone or a solution-borne nitrone. Since the product of NMRC coupling features an alkoxyamine linker, the grafting reactions can be reversed or chain insertions can be performed via nitroxide-mediated polymerization (NMP). Poly( n-butyl acrylate) ( M
Straightforward Synthesis of Symmetrical Multiblock Copolymers by Simultaneous Block Extension and Radical Coupling Reactions
Publisher: American Chemical Society (ACS)
Date: 11-11-2013
DOI: 10.1021/MA401918T
Room temperature synthesis of block copolymer nano-objects with different morphologies: via ultrasound initiated RAFT polymerization-induced self-assembly (sono-RAFT-PISA)
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0PY00461H
Abstract: The first room temperature synthesis of diblock copolymer nano-objects with different morphologies using ultrasound (990 kHz) initiated reversible addition-fragmentation chain transfer PISA (sono-RAFT-PISA) in aqueous system.
Muconic acid isomers as platform chemicals and monomers in the biobased economy
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9GC04161C
Abstract: A complete overview of the chemical and biotechnological synthesis of muconic acid, its isomerization, and valorization into chemicals and polymers is presented.
PEGylating poly(p-phenylene vinylene)-based bioimaging nanoprobes
Publisher: Elsevier BV
Date: 2021
Quantitative Product Spectrum Analysis of Poly(butyl acrylate) via Electrospray Ionization Mass Spectrometry
Publisher: American Chemical Society (ACS)
Date: 25-11-2008
DOI: 10.1021/MA801196W
A machine-readable online database for rate coefficients in radical polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1PY00544H
Abstract: An online database created and curated by an IUPAC subcommittee is introduced.
Continuous flow synthesis of core cross-linked star polymers via photo-induced copper mediated polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY00134D
Abstract: A convenient method to synthesize core cross-linked star polymers via a continuous flow photopolymerization process is developed.
Facile Synthesis of Well-Defined MDMO-PPV Containing (Tri)Block—Copolymers via Controlled Radical Polymerization and CuAAC Conjugation
Publisher: MDPI AG
Date: 24-02-2015
DOI: 10.3390/POLYM7030418
Interfacial thiol–isocyanate reactions for functional nanocarriers: a facile route towards tunable morphologies and hydrophilic payload encapsulation
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5CC05258K
Abstract: Design of nanocarriers with tunable morphology using the in situ thiol–isocyanate interfacial reactions.
Macromol. Rapid Commun. 18/2015
Publisher: Wiley
Date: 09-2015
High‐Throughput/High‐Output Experimentation in
RAFT
Polymer Synthesis
Publisher: Wiley
Date: 29-10-2021
Determining free-radical propagation rate coefficients with high-frequency lasers: Current status and future perspectives
Publisher: Wiley
Date: 19-10-2016
Abstract: Detailed knowledge of the polymerization mechanisms and kinetics of academically and industrially relevant monomers is mandatory for the precision synthesis of tailor‐made polymers. The IUPAC‐recommended pulsed‐laser polymerization–size exclusion chromatography (PLP–SEC) approach is the method of choice for the determination of propagation rate coefficients and the associated Arrhenius parameters for free radical polymerization processes. With regard to specific monomer classes—such as acrylate‐type monomers, which are very important from a materials point of view—high laser frequencies of up to 500 Hz are mandatory to prevent the formation of mid‐chain radicals and the occurrence of chain‐breaking events by chain transfer, if industrially relevant temperatures are to be reached and wide temperature ranges are to be explored (up to 70 °C). Herein the progress and state‐of‐the‐art of high‐frequency PLP–SEC with pulse repetition rates of 500 Hz is reported, with a critical collection of to‐date investigated 500 Hz data as well as future perspectives for the field. image
Determination of Propagation Rate Coefficients for Methyl and 2-Ethylhexyl Acrylate via High Frequency PLP−SEC under Consideration of the Impact of Chain Branching
Publisher: American Chemical Society (ACS)
Date: 07-12-2010
DOI: 10.1021/MA102130H
Spin capturing with nitrones: Radical coupling reactions with concurrent introduction of mid-chain functionality
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B925390D
Abstract: Nitrones are demonstrated to efficiently mediate radical coupling reactions on the ex le of the conjugation of ATRP-made polymers, yielding macromolecules with distinct functional alkoxyamine centres in mid-chain locations of the chains.
Polymer Synthesis in Continuous Flow Reactors
Publisher: Elsevier BV
Date: 08-2020
Direct synthesis of light-emitting triblock copolymers from RAFT polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0PY01358G
Abstract: We introduce a straightforward and clean method to synthesize semiconducting triblockcopolymers (tri-BCPs) using RAFT polymerization.
Improved Molecular Imprinting Based on Colloidal Particles Made from Miniemulsion: A Case Study on Testosterone and Its Structural Analogues
Publisher: American Chemical Society (ACS)
Date: 17-03-2016
Kinetic and Mechanistic Similarities between Reversible Addition Fragmentation Chain Transfer Intermediate and Acrylate Midchain Radicals
Publisher: Wiley
Date: 11-01-2011
DOI: 10.1002/POLA.24546
Rapid Oxygen Tolerant Aqueous RAFT Photopolymerization in Continuous Flow Reactors
Publisher: American Chemical Society (ACS)
Date: 07-02-2019
Organocatalyzed Photo‐Atom Transfer Radical Polymerization of Methacrylic Acid in Continuous Flow and Surface Grafting
Publisher: Wiley
Date: 21-09-2017
Abstract: The organocatalyzed photo-atom transfer radical polymerization (photoATRP) using 10-phenylphenothiazine as catalyst is studied toward its use in methacrylic acid (MAA) polymerization and surface grafting. The organocatalyzed photoATRP of methyl methacrylate (MMA) is first optimized for continuous flow synthesis in order to assess the livingness of the polymerization. MMA can be polymerized in batch and in flow however, conversions are limited by the loss of bromine functionality and hence high conversions have to be traded in with increasing dispersities. Also, MAA is polymerized successfully in continuous flow with similar limitations. Flow conditions are transferred to surface grafting from silanized silicon wafers. The presence of ATRP initiators after silanization is confirmed by secondary ion mass spectrometry and X-ray photoelectron spectroscopy. Dense polymethacrylic acid brush films are successfully produced, which is not directly accessible via classical copper-mediated ATRP techniques.
Namen und Geschlechter im Wandel
Publisher: Wiley
Date: 03-2021
Enhanced Spin-capturing Polymerization and Radical Coupling Mediated by Cyclic Nitrones
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/CH12182
Abstract: A series of cyclic nitrones have been tested for their spin-trapping activity in the enhanced spin-capturing polymerization of styrene and in nitrone-mediated radical coupling reactions. rac-2-Isopropyl-2,3-dimethyl-1-oxy-2,3-dihydro-imidazol-4-one was found to be the most efficient nitrone. The specific polystyrene macroradical addition rate to this nitrone was determined to be 8.0 × 103 L mol–1 s–1, which is by a factor of 10 higher than for previously studied compounds. Via enhanced spin-capturing polymerization, polymers in the range of oligomers to 30000 g mol–1 were obtained. A strong dependence of molecular weight on monomer conversion was observed, which can be explained by the high trapping rate. In nitrone-mediated radical coupling, almost ideal coupling of bromine-functional polymers was obtained and the successful introduction of the residual alkoxyamine functionality confirmed.
Solvent Effects on kp in Organic Media?: Statement to the Response
Publisher: Wiley
Date: 26-08-2015
Abstract: A recent response on a publication from our team investigating solvent effects on propagation rate coefficients is commented. Among other issues, we point to the fact that the response interprets only a subset of the data provided in our original contribution.
PLP Labeling in ESR Spectroscopic Analysis of Secondary and Tertiary Acrylate Propagating Radicals
Publisher: American Chemical Society (ACS)
Date: 29-12-2007
DOI: 10.1021/MA702011Q
Optimum Reaction Conditions for the Synthesis of Macromonomers Via the High‐Temperature Polymerization of Acrylates
Publisher: Wiley
Date: 21-10-2009
Abstract: Macromonomers are valuable synthetic building blocks: They can be copolymerized with low molecular weight monomers to generate brush‐like structures or serve as conjugation substrates in pericylic, metathesis, and thiolene reactions. Based on earlier reports on the facile high temperature formation of macromonomers from acrylates, a complex kinetic model is developed which accounts for the key reactions constituting the macromonomer formation process. On the basis of the kinetic model, the important rate coefficients governing acrylate polymerization (e.g., β ‐scission and termination rate coefficients of midchain radicals, backbiting and intramolecular chain transfer rate coefficients) as well as the reaction conditions (e.g., initial monomer concentration, reaction temperature, radical flux) are systematically varied and their influence on the synthetic success is critically evaluated. The systematic coefficient variation reveals that there exist optimum reaction conditions under which the high temperature macromonomers formation may be conducted with maximum success. The present study provides a concise summary of these conditions. magnified image
Investigation of the End Group Fidelity at High Conversion during Nitroxide-Mediated Acrylate Polymerizations
Publisher: American Chemical Society (ACS)
Date: 18-06-2012
DOI: 10.1021/MA300953B
Single‐pulse pulsed laser polymerization–electron paramagnetic resonance investigations into the termination kinetics of n‐butyl acrylate macromonomers
Publisher: Wiley
Date: 17-08-2012
DOI: 10.1002/POLA.26295
Abstract: The termination of model mid‐chain radicals (MCRs), which mimic radicals that occur in acrylate polymerization over a broad range of reaction conditions, has been studied by single‐pulse pulsed laser polymerization (SP‐PLP) in conjunction with electron paramagnetic resonance spectroscopy. The model radicals were generated by initiator‐fragment addition to acrylic macromonomers that were preformed prior to the kinetic experiments, thus enabling separation of termination from the propagation reaction, for these model radicals propagate sparingly, if at all, on the timescale of SP‐PLP experiments. Termination rate coefficients of the MCRs were determined in the temperature range of 0–60°C in acetonitrile and butyl propionate solution as well as in bulk macromonomer over the range of 0–100 °C. Termination rate coefficients slightly below those of the corresponding secondary radicals were deduced, demonstrating the relatively high termination activity of this species, even when undergoing MCR–MCR termination. For chain length of 10, a reduction by a factor of 6 is observed. Unusually high activation energies were found for the termination rate coefficient in these systems, with 35 kJ mol −1 being determined for bulk macromonomer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Free‐Radical Termination Kinetics Studied Using a Novel SP‐PLP‐ESR Technique
Publisher: Wiley
Date: 05-2004
Abstract: Summary: A novel method for measuring termination rate coefficients, k t , in free‐radical polymerization is presented. A single laser pulse is used to instantaneously produce photoinitiator‐derived radicals. During subsequent polymerization, radical concentration is monitored by time‐resolved electron spin resonance (ESR) spectroscopy. The size of the free radicals, which exhibits a narrow distribution increases linearly with time t , which allows the chain‐length dependence of k t to be deduced. The method will be illustrated using dodecyl methacrylate polymerization as an ex le. Two straight lines provide a very satisfactory representation of the chain‐length dependence of k t over the entire chain‐length region ( c R = radical concentration). magnified image Two straight lines provide a very satisfactory representation of the chain‐length dependence of k t over the entire chain‐length region ( c R = radical concentration).
Pulsed laser polymerization–size exclusion chromatography investigations into backbiting in ethylhexyl acrylate polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1PY01533H
Abstract: Rate coefficients for secondary radical propagation, backbiting and tertiary radical monomer addition for ethylhexyl acrylate have been determined.
Transfer Reactions in Phenyl Carbamate Ethyl Acrylate Polymerizations
Publisher: Wiley
Date: 29-10-2012
Photo-induced copper-mediated polymerization of methyl acrylate in continuous flow reactors
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3PY01762A
Abstract: Copper-mediated radical polymerization of acrylates was carried out in micro- and milliscale UV continuous flow reactors in the absence of conventional photoinitiators.
Continuous-flow self-supported seATRP using a sonicated microreactor
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2SC03608H
Abstract: Continuous-flow self-supported seATRP was realized for the first time using a novel sonicated microreactor. This provides an alternative route to scale up the eATRP process and an opportunity for a more environmentally friendly synthesis.
High Throughput Multidimensional Kinetic Screening in Continuous Flow Reactors
Publisher: Wiley
Date: 16-08-2023
Abstract: An automated high throughput multidimensional reaction screening platform based on an inline Fourier‐transform infrared spectroscopy is presented. By combining flow chemistry, machine automation and inline analysis, the platform is able to screen reactions in multidimensions (residence time, monomer concentration, degree of polymerization, reaction temperature and monomer conversion) rapidly and efficiently way. Kinetic data libraries associated with high data precision (absolute error %), high reproducibility and high data density are built with ease from the platform. To test the method, we screened the reversible addition‐fragmentation chain transfer polymerization of methyl acrylate in unmatched detail, and the ring opening metathesis polymerization of methyl‐5‐norbornene‐2‐carboxylate. The method we introduce is a key step in providing “big data” for data driven research in the future, and already at present allows for precise prediction of reaction outcomes within the high‐dimensional chemical parameter space that is screened.
Deconstructing Oligomer Distributions: Discrete Species and Artificial Distributions
Publisher: Wiley
Date: 27-08-2019
Determination of the propagation rate coefficient of acrylonitrile
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0PY00019A
Abstract: For the first time, accurate propagation rate coefficients for acrylonitrile are determined via the pulsed laser polymerization–size exclusion chromatography technique.
A Predictive machine-learning model for propagation rate coefficients in radical polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2PY01531E
Abstract: Using ridge regression, the propagation rate coefficients for radical polymerization are correlated with basic molecular properties.
Thioketone‐Mediated Polymerization with Dithiobenzoates: Proof for the Existence of Stable Radical Intermediates in RAFT Polymerization
Publisher: Wiley
Date: 03-05-2012
Abstract: A novel dithioester control agent [dimethyltetrathioterephtalate (DMTTT)] is presented for the thioketone-mediated radical polymerization (TKMP) of n-butyl acrylate. The rate of polymerization is significantly decreased in the presence of DMTTT indicating formation of dormant radical species. During polymerization, molar masses increase linearly with monomer conversion with reasonably narrow initial molar mass distributions (PDI between 1.3 and 1.8), whereas the dispersity increases during the course of the polymerization due to irreversible termination of both propagating and dormant radicals. The present results thus highlight the possibility of a mixed mechanism operating in RAFT polymerization, which combines slow fragmentation (long-lived intermediates) and intermediate radical termination.
Online tracing of molecular weight evolution during radical polymerization via high-resolution FlowNMR spectroscopy
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0PY00475H
Abstract: High-resolution FlowNMR was coupled to a continuous flow reactor to monitor polymer molecular weight evolution online by diffusion ordered NMR spectroscopy.
PPV Polymerization through the Gilch Route: Diradical Character of Monomers
Publisher: Wiley
Date: 16-11-2015
Abstract: Despite various studies on the polymerization of poly(p-phenylene vinylene) (PPV) through different precursor routes, detailed mechanistic knowledge on the in idual reaction steps and intermediates is still incomplete. The present study aims to gain more insight into the radical polymerization of PPV through the Gilch route. The initial steps of the polymerization involve the formation of a p-quinodimethane intermediate, which spontaneously self-initiates through a dimerization process leading to the formation of diradical species chain propagation ensues on both sides of the diradical or chain termination occurs by the formation of side products, such as [2.2]paracyclophanes. Furthermore, different p-quinodimethane systems were assessed with respect to the size of their aromatic core as well as the presence of heteroatoms in/on the conjugated system. The nature of the aromatic core and the specific substituents alter the electronic structure of the p-quinodimethane monomers, affecting the mechanism of polymerization. The diradical character of the monomers has been investigated with several advanced methodologies, such as spin-projected UHF, CASSCF, CASPT2, and DMRG calculations. It was shown that larger aromatic cores led to a higher diradical character in the monomers, which in turn is proposed to cause rapid initiation.
The Kinetics of enhanced spin capturing polymerization: Influence of the nitrone structure
Publisher: Wiley
Date: 08-01-2009
DOI: 10.1002/POLA.23221
Abstract: Several nitrones and one nitroso compound have been evaluated for their ability to control the molecular weight of polystyrene via the recently introduced radical polymerization method of enhanced spin capturing polymerization (ESCP). In this technique, molecular weight control is achieved (at ambient or slightly elevated temperatures) via the reaction of a growing radical chain with a nitrone forming a macronitroxide. These nitroxides subsequently react rapidly and irreversibly with propagating macroradicals forming polymer of a certain chain length, which depends on the nitrone concentration in the system. Via evaluation of the resulting number‐average molecular weight, M n , at low conversions, the addition rate coefficient of the growing radicals onto the different nitrones is determined and activation energies are obtained. For the nitrones N ‐ tert ‐butyl‐α‐phenylnitrone (PBN), N ‐methyl‐α‐phenylnitrone (PMN), and N ‐methyl‐α‐(4‐bromo‐phenyl) nitrone ( p B‐PMN), addition rate coefficients, k ad,macro , in a similar magnitude to the styrene propagation rate coefficient, k p , are found with spin capturing constants C SC (with C SC = k ad,macro / k p ) ranging from 1 to 13 depending on the nitrone and on temperature. Activation energies between 23.6 and 27.7 kJ mol −1 were deduced for k ad,macro , congruent with a decreasing C SC with increasing temperature. Almost constant M n over up to high monomer to polymer conversions is found when C SC is close to unity, while increasing molecular weights can be observed when the C SC is large. From temperatures of 100 °C onward, reversible cleavage of the alkoxyamine group can occur, superimposing a reversible activation/deactivation mechanism onto the ESCP system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1098–1107, 2009
Controlling Molecular Weight Distributions Through the Mixing of Low Dispersity Polymer Samples: A Predictive Framework
Publisher: American Chemical Society (ACS)
Date: 06-06-2019
DOI: 10.26434/CHEMRXIV.8233460.V1
Abstract: The physical properties of polymer s les are dependent on the overall shape and breadth of the molecular weight distribution (MWD). A small number of methods are available to tune the shape and characteristics of MWDs based on influencing controlled radical polymerizations and on mixing of in idual distributions. However, no systematic framework exists to date to predict the characteristics and shapes of artificial MWDs prior the experiments. In this work we present such framework based on interpolation of in idual distributions.
Precision Polymer Design in Microstructured Flow Reactors: Improved Control and First Upscale at Once
Publisher: Wiley
Date: 04-11-2016
Ultrafast PhotoRAFT Block Copolymerization of Isoprene and Styrene Facilitated through Continuous‐Flow Operation
Publisher: Wiley
Date: 05-10-2018
Abstract: Polymers made from isoprene and styrene resemble an important class of synthetic macromolecules found in a wide range of everyday commodity products. Their synthesis is usually limited to radical emulsion or anionic polymerization. Herein, we report on ultrafast photoiniferter reversible addition-fragmentation chain transfer (RAFT) polymerization of isoprene and styrene in a continuous-flow microreactor. The cooperative action of a high photoinitiation efficiency and use of elevated temperatures considerably reduces the reaction times to less than half an hour to give high monomer conversions, allowing for the first time polyisoprene to be yielded from controlled radical polymerization in high definition and reasonable reaction times. High chain-end fidelities are maintained and block copolymers were prepared including a polystyrene-block-polyisoprene-block-polystyrene (PS-b-PI-b-PS) triblock copolymer.
The role of mid‐chain radicals in acrylate free radical polymerization: Branching and scission
Publisher: Wiley
Date: 27-10-2008
DOI: 10.1002/POLA.23071
Synthesis of a Macromonomer Library from High‐Temperature Acrylate Polymerization
Publisher: Wiley
Date: 12-2009
Abstract: The auto-initiated high temperature acrylate polymerization represents a versatile route for the synthesis of macromonomer building blocks. Various macromonomers were synthesized via this route based on methyl, ethyl, n-butyl, t-butyl, 2-ethylhexyl, isobornyl and 2-[[(butylamino)carbonyl]oxy]ethyl acrylate. The synthesis requires a temperature of 140 °C and is carried out in a 5 wt.-% solution of hexyl acetate. The macromonomer library is fully characterized via electrospray ionization mass spectrometry (ESI-MS). The amount of macromonomers containing the geminal double bond lies in between 82 and 95%, depending on the monomer type. The achievable molecular weight of the macromonomers is located between 800 and 2 000 g·mol(-1) with a polydispersity of close to 1.6. In addition, it is demonstrated that radical initiators are useful add-ons (to circumvent the inhibition time observed during initiator-free synthesis) without interfering in the actual polymerization as no initiator-fragment containing products are identified via high resolution mass spectrometry.
Revealing model dependencies in 'Assessing the RAFT equilibrium constant via model systems: An EPR study'
Publisher: Wiley
Date: 20-10-2011
Abstract: In a recent article (W. Meiser, M. Buback, Assessing the RAFT Equilibrium Constant via Model Systems: An EPR Study, Macromol. Rapid Commun. 2011, 18, 1490-1494), it is claimed that evidence is found that unequivocally proves that quantum mechanical calculations assessing the equilibrium constant and fragmentation rate coefficients in dithiobenzoate-mediated reversible addition fragmentation transfer (RAFT) systems are beset with a considerable uncertainty. In the present work, we show that these claims made by Meiser and Buback are beset with a model dependency, as a critical key parameter in their data analysis - the addition rate coefficient of the radicals attacking the C=S double bond in the dithiobenzoate - induces a model insensitivity into the data analysis. Contrary to the claims made by Meiser and Buback, their experimental results can be brought into agreement with the quantum chemical calculations if a lower addition rate coefficient of cyanoisopropyl radicals (CIP) to the CIP dithiobenzoate (CPDB) is assumed. To resolve the model dependency, the addition rate coefficient of CIP radicals to CPDB needs to be determined as a matter of priority.
Laser Single Pulse Initiated RAFT Polymerization for Assessing Chain‐Length Dependent Radical Termination Kinetics
Publisher: Wiley
Date: 02-05-2005
Precise macromolecular engineering via continuous-flow synthesis techniques
Publisher: Springer Science and Business Media LLC
Date: 09-2017
Telescoped continuous flow synthesis of phenyl acrylamide
Publisher: Springer Science and Business Media LLC
Date: 27-08-2020
Photo-induced ring-closure: Via a looped flow reactor
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7RE00124J
Abstract: Looped flow processes are an efficient and versatile tool to synthesize cyclic macromolecular materials.
From monomer to micelle: a facile approach to the multi-step synthesis of block copolymers via inline purification
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3SC01819A
Abstract: A one-pass continuous flow strategy to form block copolymer nanoaggregates directly from monomers is presented.
Kinetic Control of Aggregation Shape in Micellar Self‐Assembly
Publisher: Wiley
Date: 19-08-2019
Molecularly Imprinted Polymers
Publisher: Elsevier
Date: 2016
“Clicking” Polymers or Just Efficient Linking: What Is the Difference?
Publisher: Wiley
Date: 03-12-2010
One-pot multifunctional polyesters by continuous flow organocatalysed ring-opening polymerisation for targeted and tunable materials design
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2PY00088A
Abstract: We integrate continuous flow organocatalysed ring-opening polymerisation with a core-grafting strategy to rapidly and readily prepare multifunctional, processable polyesters. Their potential use in materials applications is subsequently highlighted.
The Kinetics of n‐Butyl Acrylate Radical Polymerization Revealed in a Single Experiment by Real Time On‐line Mass Spectrometry Monitoring
Publisher: Wiley
Date: 26-05-2017
Mapping Photolysis Product Radical Reactivities via Soft Ionization Mass Spectrometry in Acrylate, Methacrylate, and Itaconate Systems
Publisher: American Chemical Society (ACS)
Date: 16-08-2007
DOI: 10.1021/MA070626A
Self‐directed formation of uniform unsaturated macromolecules from acrylate monomers at high temperatures
Publisher: Wiley
Date: 18-04-2008
DOI: 10.1002/POLA.22676
RAFT kinetics revisited: Revival of the RAFT debate
Publisher: Wiley
Date: 22-07-2011
DOI: 10.1002/POLA.24857
Abstract: Recently, two electron spin resonance (ESR)‐based methods for the determination of addition and fragmentation rate coefficients in dithiobenzoate‐mediated reversible addition fragmentation transfer (RAFT) polymerization were introduced, one being based on a spin‐trapping method and the other on single‐laser pulse initiation in conjunction with ESR detection at microsecond time resolution. For the RAFT‐intermediate radical fragmentation rate, coefficient data differing by six orders of magnitude were obtained, which cannot be explained by the usual model dependencies, that is the so‐called cross‐termination versus stable intermediate model. Even under consideration of fast cross‐termination in both cases, the large difference persists. Both the experimental designs are thus critically reviewed to identify potential error sources and to explain the vast difference in the in idual results. Both techniques appear to be robust and only small interferences could be identified. Finally, recommendations for the refinement of the in idual techniques are given to achieve a consistent kinetic picture of the underpinning reaction equilibria. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
PLP−ESR Monitoring of Midchain Radicals in n-Butyl Acrylate Polymerization
Publisher: American Chemical Society (ACS)
Date: 14-05-2005
DOI: 10.1021/MA050198D
A Study into the Stability of 3,6-Dihydro-2H-thiopyran Rings: Key Linkages in the RAFT Hetero-Diels−Alder Click Concept
Publisher: American Chemical Society (ACS)
Date: 14-10-2008
DOI: 10.1021/MA8013959
Precision synthesis of acrylate multiblock copolymers from consecutive microreactor RAFT polymerizations
Publisher: Wiley
Date: 14-02-2013
DOI: 10.1002/POLA.26593
Abstract: Well‐defined acrylate RAFT polymers and multiblock‐copolymers have been synthesized via the use of a continuous‐flow microreactor, in which polymerizations could be executed in 5−20 min reaction time. First, Poly(n‐butyl acrylate) (P n BuA) was synthesized in the micro‐flowreactor by using two different trithiocarbonate RAFT agents. Reaction time and reaction temperature were optimized and collected s les were directly studied with NMR, SEC and ESI‐MS to determine conversion, molar mass and end group fidelity. Using the continuous flow technique, highly reproducible and fast polymerizations yielded quantitatively functionalized P n BuA in a very facile and efficient manner. One batch of RAFT acrylate polymer with a molar mass of 1100 g mol −1 and excellent end group fidelity was employed as a macro‐RAFT agent for the subsequent copolymerization with different acrylate monomers (2‐ethylhexyl acrylate, t ‐butyl acrylate, n ‐butyl acrylate). Using this procedure, a sequential multiblock‐copolymer ( M n = 31,200 g mol −1 , PDI = 1.46) consisting of five consecutive acrylate blocks was synthesized. This study clearly demonstrates the potential of using a continuous‐flow microreactor for subsequent RAFT polymerizations towards well‐defined multiblock‐copolymers. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013, 51, 2366–2374
Alcohol-based PISA in batch and flow: exploring the role of photoinitiators
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY00166B
Abstract: Polymerization-induced self-assembly (PISA) via PhotoRAFT (photoinduced reversible addition–fragmentation radical transfer) was investigated in polar solvents via continuous flow reactors.
Formation of triblock copolymers via a tandem enhanced spin capturing-nitroxide-mediated polymerization reaction sequence
Publisher: Wiley
Date: 09-09-2011
DOI: 10.1002/POLA.24970
Abstract: The preparation of ABA‐type block copolymers via tandem enhanced spin capturing polymerization (ESCP) and nitroxide‐mediated polymerization (NMP) processes is explored in‐depth. Midchain alkoxyamine functional polystyrenes ( M n = 6200, 12,500 and 19,900 g mol −1 ) were chain extended with styrene as well as tert ‐butyl acrylate at elevated temperature NMP conditions ( T = 110 °C) generating a tandem ESCP‐NMP sequence. Although the chain extensions and thus the block copolymer formation processes function well (yielding in the case of the chain extension with styrene number average molecular weights of up to 20,800 g mol −1 (PDI = 1.22) when the 6200 g mol −1 precursor is used and up to 67,500 g mol −1 (PDI = 1.36) when the 19,900 g mol −1 precursor is used and 21,600 g mol −1 (PDI = 1.17) as well as 37,100 g mol −1 (PDI = 1.21) for the tert ‐butyl acrylate chain extensions for the 6200 and 12,500 g mol −1 precursors, respectively), it is also evident that the efficiency of the block copolymer formation process decreases with an increasing chain length of the ESCP precursor macromolecules (i.e., for the 19,900 g mol −1 ESCP precursor no efficient chain extension with tert ‐butyl acrylate can be observed). For the polystyrene‐ block ‐ tert ‐butyl acrylate‐ block ‐polystyrene polymers, the molecular weights were determined via triple detection SEC using light scattering and small‐angle X‐ray scattering. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.
Learning from Peptides to Access Functional Precision Polymer Sequences
Publisher: Wiley
Date: 07-2019
Abstract: Functional precision polymers based on monodisperse oligo(N-substituted acrylamide)s and oligo(2-substituted-α-hydroxy acid)s have been synthesized. The discrete sequences originate from a direct translation of side-chain functionality sequences of a peptide with well-studied properties. The peptide was previously selected to solubilize the photosensitizer meta-tetra(hydroxyphenyl)chlorin. The resulting peptidomimetic formulation additives preserve the drug solubilization and release characteristics of the parent peptide. In some cases, superior properties are obtained, reaching up to 40 % higher payloads and 27-times faster initial drug release.
Quantifying the eficiency of photoinitiation processes in methyl methacrylate free radical polymerization via electrospray ionization mass spectrometry
Publisher: American Chemical Society (ACS)
Date: 17-02-2009
DOI: 10.1021/MA802308Z
Comprehensive high-throughput screening of photopolymerization under light intensity variation using inline NMR monitoring
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3PY00190C
Abstract: Continuous flow chemistry offers an exceptionally high degree of operational flexibility to handle photochemical transformations.
Synthesis of (Bio)‐Degradable Poly(β‐thioester)s via Amine Catalyzed Thiol−Ene Click Polymerization
Publisher: Wiley
Date: 22-10-2012
Simple and secure data encryption via molecular weight distribution fingerprints
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0PY01071E
Abstract: A method for encryption and safe transmission of data in the shape of molecular weight distributions (MWD) is presented.
Facile photo-flow synthesis of branched poly(butyl acrylate)s
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7RE00013H
Abstract: We present the synthesis of branched poly(butyl acrylate)s using photo-induced free radical polymerization of ( n / t )-butyl acrylate in the presence of tri(propylene glycol) diacrylate (TPGDA) as a crosslinker and varying amounts of dodecanethiol (DDT) as a chain transfer agent to prevent macroscopic gelation.
Control of methyl methacrylate radical polymerization via Enhanced Spin Capturing Polymerization (ESCP)
Publisher: Elsevier BV
Date: 08-2010
PPV-Based Conjugated Polymer Nanoparticles as a Versatile Bioimaging Probe: A Closer Look at the Inherent Optical Properties and Nanoparticle–Cell Interactions
Publisher: American Chemical Society (ACS)
Date: 27-06-2016
DOI: 10.1021/ACS.BIOMAC.6B00574
Abstract: Conjugated polymers have attracted significant interest in the bioimaging field due to their excellent optical properties and biocompatibility. Tailor-made poly(p-phenylenevinylene) (PPV) conjugated polymer nanoparticles (NPs) are in here described. Two different nanoparticle systems using poly[2-methoxy-5-(3',7'-dimethoxyoctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and a functional statistical copolymer 2-(5'-methoxycarbonylpentyloxy)-5-methoxy-1,4-phenylenevinylene (CPM-MDMO-PPV), containing ester groups on the alkoxy side chains, were synthesized by combining miniemulsion and solvent evaporation processes. The hydrolysis of ester groups into carboxylic acid groups on the CPM-MDMO-PPV NPs surface allows for biomolecule conjugation. The NPs exhibited excellent optical properties with a high fluorescent brightness and photostability. The NPs were in vitro tested as potential fluorescent nanoprobes for studying cell populations within the central nervous system. The cell studies demonstrated biocompatibility and surface charge dependent cellular uptake of the NPs. This study highlights that PPV-derivative based particles are a promising bioimaging probe and can cater potential applications in the field of nanomedicine.
Comprehensive control over molecular weight distributions through automated polymerizations
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9PY01013K
Abstract: Automated synthesis by mixing of in idual polymer distributions to tune the shape and properties of artificial molecular weight distributions.
Magnetic Force Microscopy of in a Polymer Matrix Embedded Single Magnetic Nanoparticles
Publisher: Wiley
Date: 21-12-2018
Sequence-defined nucleobase containing oligomers via reversible addition–fragmentation chain transfer single monomer addition
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9PY01853K
Abstract: Nucleobase acrylate monomers have been synthesized and monodisperse tetramers with any order of bases are created via single monomer insertion reactions in a RAFT process.
A Detailed Investigation of the Free Radical Copolymerization Behavior of n-Butyl Acrylate Macromonomers
Publisher: American Chemical Society (ACS)
Date: 04-08-2011
DOI: 10.1021/MA201345M
The block copolymer shuffle in size exclusion chromatography: the intrinsic problem with using elugrams to determine chain extension success
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1PY00210D
Abstract: Is an increase in hydrodynamic volume always expected in block copolymer synthesis? Why SEC is sometimes not the last word.
Synthesis of Functional Polymer Particles from Morita–Baylis–Hillman Polymerization
Publisher: Wiley
Date: 02-11-2018
Abstract: Functional synthetic polymers are frequently explored for their use in the biomedical field. To fulfill the stringent demands of biodegradability and compatibility, the materials need to be versatile and tunable. Post-modification is often considered challenging for well-known degradable materials like poly(lactic acid) because of their chemical inertness. In this work a procedure is proposed to produce densely functionalized polymer particles using oligomeric precursors synthesized via the Morita-Baylis-Hillman reaction. This allows for a variety of post-modification reactions to serve bio-conjugation or tuning of the material properties. The particles are subjected to basic media and found to be degradable. Furthermore, cytotoxicity tests confirm good biocompatibility. Finally, as a proof of concept to demonstrate the versatility of the particles, post-modification reactions are carried out through the formation of imines.
Anionic PPV polymerization from the sulfinyl precursor route: Block copolymer formation from sequential addition of monomers
Publisher: Elsevier BV
Date: 02-2013
RAFT multiblock reactor telescoping: from monomers to tetrablock copolymers in a continuous multistage reactor cascade
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY00585G
Abstract: Well-defined multiblock copolymers were synthesized via reversible addition-fragmentation chain transfer radical polymerization in a fully continuous multireactor cascade.
Chapter 6. Recent Developments in Nitroxide Mediated Polymerization
Publisher: Royal Society of Chemistry
Date: 2015
2D laser lithography on silicon substrates via photoinduced copper-mediated radical polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7CC08444G
Abstract: A 2D laser lithography protocol for controlled grafting of polymer brushes in a single-step is presented.
Nitrone-mediated radical coupling reactions: A new synthetic tool exemplified on dendrimer synthesis
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC10322A
Abstract: A synthetic strategy employing nitrones as radical spin traps is presented on the ex le of the efficient generation of novel dendrimers via a combination of radical and classical ‘click’ chemistry.
Introduction to the themed collection on sustainable polymers
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2PY90028A
Abstract: Antoine Buchard and Tanja Junkers introduce the Polymer Chemistry themed collection on Sustainable Polymers.
Critically evaluated rate coefficients in radical polymerization – 7. Secondary-radical propagation rate coefficients for methyl acrylate in the bulk
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3PY00774J
Abstract: Benchmark propagation rate coefficient ( k p ) data for the radical polymerization of methyl acrylate are provided.
Kilohertz Pulsed‐Laser‐Polymerization: Simultaneous Determination of Backbiting, Secondary, and Tertiary Radical Propagation Rate Coefficients for tert‐Butyl Acrylate
Publisher: Wiley
Date: 14-03-2016
Abstract: For the first time, a 1000 Hz pulse laser has been applied to determine detailed kinetic rate coefficients from pulsed laser polymerization–size exclusion chromatography experiments. For the monomer tert ‐butyl acrylate, apparent propagation rate coefficients k p app have been determined in the temperature range of 0–80 °C. k p app in the range of few hundreds to close to 50 000 L·mol –1 ·s –1 are determined for low and high pulse frequencies, respectively. The apparent propagation coefficients show a distinct pulse‐frequency dependency, which follows an S‐shape curve. From these curves, rate coefficients for secondary radial propagation ( k p SPR ), backbiting ( k bb ), midchain radical propagation ( k p tert ), and the (residual) effective propagation rate ( k p eff ) can be deduced via a herein proposed simple Predici fitting procedure. For k p SPR , the activation energy is determined to be (17.9 ± 0.6) kJ·mol –1 in excellent agreement with literature data. For k bb , an activation energy of (25.9 ± 2.2) kJ·mol –1 is deduced. image
Pushing the limit: Pulsed laser polymerization of n-butyl acrylate at 500 Hz
Publisher: American Chemical Society (ACS)
Date: 04-11-2008
DOI: 10.1021/MA8020932
Discovery of an Anionic Polymerization Mechanism for High Molecular Weight PPV Derivatives via the Sulfinyl Precursor Route
Publisher: American Chemical Society (ACS)
Date: 13-09-2011
DOI: 10.1021/MA201453S
Understanding electrostatic and magnetic forces in magnetic force microscopy: towards single superparamagnetic nanoparticle resolution
Publisher: IOP Publishing
Date: 27-07-2018
Profluorescent PPV-Based Micellar System as a Versatile Probe for Bioimaging and Drug Delivery
Publisher: American Chemical Society (ACS)
Date: 14-11-2016
DOI: 10.1021/ACS.BIOMAC.6B01653
Abstract: Although micelles are commonly used for drug delivery purposes, their long-term fate is often unknown due to photobleaching of the fluorescent labels or the use of toxic materials. Here, we present a metal-free, nontoxic, nonbleaching, fluorescent micelle that can address these shortcomings. A simple, yet versatile, profluorescent micellar system, built from hiphilic poly(p-phenylenevinylene) (PPV) block copolymers, for use in drug delivery applications is introduced. Polymer micelles made from PPV show excellent stability for up to 1 year and are successfully loaded with anticancer drugs (curcumin or doxorubicin) without requiring introduction of physical or chemical cross-links. The micelles are taken up efficiently by the cells, which triggers disassembly, releasing the encapsulated material. Disassembly of the micelles and drug release is conveniently monitored as fluorescence of the single polymer chains appear, which enables not only to monitor the release of the payload, but in principle also the fate of the polymer over longer periods of time.
Direct Access to Dithiobenzoate RAFT Agent Fragmentation Rate Coefficients by ESR Spin‐Trapping
Publisher: Wiley
Date: 30-10-2014
Abstract: The β-scission rate coefficient of tert-butyl radicals fragmenting off the intermediate resulting from their addition to tert-butyl dithiobenzoate-a reversible addition-fragmentation chain transfer (RAFT) agent-is estimated via the recently introduced electron spin resonance (ESR)-trapping methodology as a function of temperature. The newly introduced ESR-trapping methodology is critically evaluated and found to be reliable. At 20 °C, a fragmentation rate coefficient of close to 0.042 s(-1) is observed, whereas the activation parameters for the fragmentation reaction-determined for the first time-read EA = 82 ± 13.3 kJ mol(-1) and A = (1.4 ± 0.25) × 10(13) s(-1) . The ESR spin-trapping methodology thus efficiently probes the stability of the RAFT adduct radical under conditions relevant for the pre-equilibrium of the RAFT process. It particularly indicates that stable RAFT adduct radicals are indeed formed in early stages of the RAFT poly-merization, at least when dithiobenzoates are employed as controlling agents as stipulated by the so-called slow fragmentation theory. By design of the methodology, the obtained fragmentation rate coefficients represent an upper limit. The ESR spin-trapping methodology is thus seen as a suitable tool for evaluating the fragmentation rate coefficients of a wide range of RAFT adduct radicals.
Machine-Learning Based Prediction of Kinetic Rate Coefficients in Radical Polymerization
Publisher: American Chemical Society (ACS)
Date: 04-11-2022
Embedding multiple site-specific functionalities into polymer chains via nitrone-mediated radical coupling reactions
Publisher: Wiley
Date: 03-2017
DOI: 10.1002/POLA.24639
Abstract: A facile method to generate polymer materials with embedded functional groups at known and precise positions along the polymer backbone is described. In the presented approach, well‐defined bifunctional poly(isobornyl acrylate)s preformed via atom transfer radical polymerization (ATRP) containing α,ω‐bromo end groups are reactivated and subsequently coupled in a stepwise manner via the nitrone‐mediated radical coupling (NMRC) technique. The generated polymers contain on average four nitrone moieties at evenly spaced locations. The number of embedded functionalities, and thus, the size of the polymer is limited by disproportionation reactions occurring during the nitroxide termination sequence. Using the nitrone as a functional carrier, secondary functionalities can be incorporated into the polymer with ease. To exemplify such an approach, an alkyne‐functionalized nitrone is used to construct a multisegment structure via NMRC reactions followed by postmodification of the obtained polymers with 3‐mercaptopropionic acid via UV‐induced thiol‐yne reactions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Macromonomers from AGET Activation of Poly(n-butyl acrylate) Precursors: Radical Transfer Pathways and Midchain Radical Migration
Publisher: American Chemical Society (ACS)
Date: 24-08-2012
DOI: 10.1021/MA301233V
Synthesis of MDMO‐PPV Nanoparticles Via In Situ Sulfinyl Precursor Route Polymerization in Miniemulsion
Publisher: Wiley
Date: 08-07-2013
Scalable Aqueous Reversible Addition–Fragmentation Chain Transfer Photopolymerization-Induced Self-Assembly of Acrylamides for Direct Synthesis of Polymer Nanoparticles for Potential Drug Delivery App
Publisher: American Chemical Society (ACS)
Date: 16-05-2019
Flash-synthesis of low dispersity PPVviaanionic polymerization in continuous flow reactors and block copolymer synthesis
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0PY01245A
Abstract: Low dispersity poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)]-1,4-phenylenevinylene (MDMO-PPV) with well-defined end-groups is made available by performing the anionic polymerization in a continuous tubular reactor under flash chemistry conditions.
Controlled synthesis of MDMO-PPV and block copolymers made thereof
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2PY00551D
Abstract: Via CBr 4 -mediation bromine functional MDMO-PPVs with controlled molecular weight were obtained and chain extended in further ATRP reactions.
Photoiniferter surface grafting of poly(methyl acrylate) using xanthates
Publisher: Wiley
Date: 22-05-2019
DOI: 10.1002/POLA.29405
Synthesis of well-defined PPV containing block polymers with precise endgroup control by a dual-initiator strategy
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3PY00303E
Abstract: The initiator efficiency in PPV polymerization was tested and PPV- b -(P- t BuA) block copolymers were synthesized. Via hydrolysis hiphilic materials undergoing micelle formation were obtained.
Free-Radical Polymerization Kinetics of 2-Acrylamido-2-methylpropanesulfonic Acid in Aqueous Solution
Publisher: American Chemical Society (ACS)
Date: 21-12-2005
DOI: 10.1021/MA051187N
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