Effects of Initiator Homolysis Rate Constant on Kinetics and Chain Length Distribution in Living Free-Radical Polymerization

He, Junpo; Zhang, Hongdong; Li, Li; Li, Chengming; Cao, Jizhuang; Yang, Yuliang

doi:10.1295/polymj.31.585

Cited by 13 publications

(7 citation statements)

References 35 publications

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“…Molecular weight and molecular weight distribution were measured with gel permeation chromatography (GPC) on a Waters Instrument-302 (elutent: tetrahydrofurane, 40°C, 1.0 ml/min; two polystyrene columns: G2000Ha and G500000Ha, calibrated with standard polystyrene). The monomer conversion was determined with NETZSCH TGA 204 as described elsewhere [13]. 1 H nuclear magnetic resonance (NMR) to characterize the polymer structure was studied with a Bruker spectrometer (300 MHz).…”

Section: Methodsmentioning

confidence: 99%

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Nitroxide-controlled free radical copolymerization of styrene and acrylonitrile monitored by electron spin resonance and fourier transform infrared technique in situ

et al. 2001

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Nitroxide-mediated homopolymerization of styrene (St) and copolymerization of styrene and acrylonitrile (An) were monitored respectively by electron spin resonance and Fourier transform infrared technique in situ, and the polymerization kinetics was investigated in detail. Homopolymerization of St was well controlled in the presence of 4-hydroxyl-2,2,6,6-tetramethyl-l-piperidinyloxy (HTEMPO, N*) at high temperature. The initiation reactions and polymerization rates were changed by varying initiators, such as benzoyl peroxide (BPO), 2,2-azobis-isobutylonitrile (AIBN) and dicyclohexyl dicarbonate peroxide (DCPO) because of the different half-period values of the initiators. For the St system containing the DCPO with longer half-period value, the reaction rate was enhanced and the final conversion was increased because the larger amount of the DCPO residual released continuously the excess radicals to increase growing radical concentration. But the polydispersity of the resulting polymer became somewhat larger. The copolymerization of St and An with AIBN as initiator in the presence of HTEMPO was also tamed in the living fashion of stable free radical polymerization in the range of the total monomer conversion below 40%. The hydrogen-abstracting effect on the pen-

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Section: Methodsmentioning

confidence: 99%

“…Methods for improving the polymerization rate were advanced to be applied successfully in experimental work [13,14]. The copolymerization systems, such as St/An, St/hydroxylpropyl methyacrylate (HPMA), St/vinyl pyridine (VP) were tested on proceeding in SFRP.…”

Section: Introductionmentioning

confidence: 99%

Nitroxide-controlled free radical copolymerization of styrene and acrylonitrile monitored by electron spin resonance and fourier transform infrared technique in situ

et al. 2001

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“…Controlled/“living” radical polymerizations are simulated in a straightforward application of the GSSA, often yielding great insight into the results of experimental studies. Mechanisms studied by GSSA include nitroxide‐mediated,93–98 atom transfer radical polymerization (ATRP) with varying initiator functionality,99, 100 copolymerization by ATRP,84, 101 length‐dependent termination rates in ATRP,102 the cross reaction between dithioester and alkoxyamine used in reversible addition‐fragmentation chain transfer (RAFT),103 and RAFT polymerization of methyl acrylate mediated by cumyldithiobenzoate 104. Because the activation/deactivation processes involved in reversible termination type controlled polymerizations are typically much faster than the other reaction channels, these processes occur predominantly and can increase computation time significantly relative to free‐radical polymerization.…”

Section: Computer Simulation Approaches For Polymerization In Bulkmentioning

confidence: 99%

Progress in Computer Simulation of Bulk, Confined, and Surface‐initiated Polymerizations

Bain

Turgman‐Cohen

Genzer

2012

Macro Theory & Simulations

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In this article we provide a brief summary of computational techniques applied to investigate polymerization reactions in general, with a focus on systems under confinement and initiated from surfaces. We concentrate on two major classes of techniques, i.e., stochastic methods and molecular modeling. We describe the major principles of the two classes of methodologies and point out their strengths and weaknesses. We review a variety of studies from the literature and conclude with an outlook of these two classes of computer simulation approaches as they are applied to “grafting from” polymerizations.

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“…We have performed the study on improving the SFRP rate by varying the initiators and the addition procedure 22–24. Chen and coworkers25–30 found a new kind of Cu‐bipyridine (bpy) complex system that carried ATRP of MMA out at low temperatures (≤80 °C).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of well‐defined multigraft copolymers by a two‐step living radical polymerization with nitroxyl‐functionalized poly(methyl methacrylate)

Feng

Liu

et al. 2002

J. Polym. Sci. A Polym. Chem.

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Novel multigraft copolymers of poly(methyl methacrylate-graft-polystyrene) (PMMA-g-PS) in which the number of graft PS side chains was varied were prepared by a subsequent two-step living radical copolymerization approach. A polymerizable 4-vinylbezenyl 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) monomer (STEMPO), which functioned as both a monomer and a radical trapper, was placed in a low-temperature atom transfer radical polymerization (60°C) process of methyl methacrylate with ethyl 2-bromopronionate (EPNBr) as an initiator to gain ethyl pronionate-capped prepolymers with TEMPO moieties, PMMA-STEMPOs. The number of TEMPO moieties grafted on the PMMA backbone could be designed by varying STEMPO/EPNBr, for example, the ratios of 1/2, 2/3, or 3/4 gained one, two, or three graft TEMPO moieties, respectively. The resulting prepolymers either as a macromolecular initiator or a trapper copolymerized with styrene in the control of stable free-radical polymerization at an elevated temperature (120°C), producing the corresponding multigraft copolymers, PMMA-g-PSs. The nitroxyl-functionalized PMMA prepolymers produced a relatively high initiation efficiency (Ͼ0.8) as a result of the stereohindrance and slow diffusion of TEMPO moieties connected on the long PMMA backbone. The polymerization kinetics in two processes showed a living radical polymerization characteristic. The molecular structures of these prepolymers and graft copolymers were well characterized by combining Fourier transform infrared spectroscopy, gel permeation chromatography, chemical element analysis, and 1 H NMR.

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Effects of Initiator Homolysis Rate Constant on Kinetics and Chain Length Distribution in Living Free-Radical Polymerization

Cited by 13 publications

References 35 publications

Nitroxide-controlled free radical copolymerization of styrene and acrylonitrile monitored by electron spin resonance and fourier transform infrared technique in situ

Nitroxide-controlled free radical copolymerization of styrene and acrylonitrile monitored by electron spin resonance and fourier transform infrared technique in situ

Progress in Computer Simulation of Bulk, Confined, and Surface‐initiated Polymerizations

Synthesis of well‐defined multigraft copolymers by a two‐step living radical polymerization with nitroxyl‐functionalized poly(methyl methacrylate)

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