Microstructures in poly(vinyl alcohol-co-crotonic acid) studied by proton-NMR and carbon-13-NMR

Amiya, Shigetoshi; Uetsuki, Masao

doi:10.1021/ma00229a033

Cited by 28 publications

(25 citation statements)

References 2 publications

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“…One of the main reasons for the broadening is most probably the accumulation of the less reactive primary C-SC(S)OR 0 terminal originating from the head-to-head addition, which is inherent in the VAc radical polymerization. [44][45][46][47][48] These results suggest that Mn 2 (CO) 10 induces the controlled/living radical polymerization of VAc even in conjunction with a xanthate via the reversible activation of the C-SC(S)OR terminal.…”

Section: Measurementsmentioning

confidence: 78%

Mn2(CO)10-Induced RAFT Polymerization of Vinyl Acetate, Methyl Acrylate, and Styrene

2009

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A dinuclear manganese complex [Mn 2 (CO) 10 ] induced the controlled/living radical polymerization of various conjugated and unconjugated vinyl monomers including vinyl acetate, methyl acrylate, and styrene in conjunction with dithiocarbonyl compounds [R-SC(S)Z] under weak visible light at 40 C. The obtained polymers had controlled molecular weights, narrow molecular weight distributions, and well-defined chain-end groups originating from R-SC(S)Z, as indicated by SEC, 1 H NMR, and MALDI-TOF-MS analyses. The polymerization most probably proceeds via the reversible activation of the C-SC(S)Z bond by Á Mn(CO) 5 via the metal-catalyzed process and/or by the carbon-centered radical species via the additionfragmentation chain transfer (RAFT) process.KEY WORDS: Vinyl Acetate / Acrylate / Styrene / Living Radical Polymerization / RAFT Polymerization / Manganese Complex / Various aspects of the controlled/living radical polymerization have been significantly developed in this decade, including a variety of initiating systems, controllable monomers, polymer structures, fusion with other substances, and applications to functional materials. Among the numerous initiating systems, there are now three representatives in terms of wide applicability and good controllability; i.e., the nitroxide-mediated radical polymerization (NMP), 1,2 metal-catalyzed living radical polymerization or atom transfer radical polymerization (ATRP), [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and reversible addition-fragmentation chain transfer (RAFT) 18 polymerization or macromolecular design via interchange of xanthate (MADIX). 19 Although the components and the mechanisms are different, they are all based on the reversible transient activation of the dormant covalent species into the growing radical species. However, each system has its own characteristics or features due to the differences, which suggests that the choice of initiating systems is important depending on the monomers, conditions, purposes, etc.The metal-catalyzed living radical polymerization or ATRP is one of the best methods in terms of the well-defined architecture of the polymers from a variety of conjugated monomers, such as methacrylates, acrylates, acrylamides, acrylonitrile, and styrenes. This polymerization is generally initiated by the carbon radical generated from the alkyl halide upon the activation of the carbon-halogen bond by the transition metal catalyst, and then proceeds via the metalcatalyzed reversible activation of the carbon-halogen terminal into the growing radical species. One growing polymer chain end is thus generated from one carbon-halogen bond, which can permit the well-defined polymer synthesis. Although various transition metals, such as ruthenium, 3 20 The choice of the metal complexes including metals and ligands as well as the halides is important for the precise control of the polymerizations depending on the monomers.In contrast, the RAFT/MADIX system with the dithiocarbonyl compounds [R-SC(S)Z] is one of the most widely applica...

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Section: Measurementsmentioning

confidence: 78%

Mn2(CO)10-Induced RAFT Polymerization of Vinyl Acetate, Methyl Acrylate, and Styrene

2009

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“…9,[15][16][17][18][19] Tail radicals and MCRs could not be detected via EPR in a study of Kattner and Buback,9 while in NMR studies contradictory findings regarding the importance of backbiting have been reported. [15][16][17][18][19] It should however be noted that for VAc radical polymerization, the analysis of NMR and EPR spectra is significantly complicated due to the occurrence of head-to-head propagation, possibly leading to low concentrations of tail and mid-chain radicals that could be close to the detection limits. An interesting alternative approach is ab initio based kinetic modeling, 20,21 especially for a complicated reaction mechanism involving many side reactions, as in the case of VAc radical polymerization.…”

Section: Introductionmentioning

confidence: 95%

Ab initio based kinetic Monte Carlo analysis to unravel the propagation kinetics in vinyl acetate pulsed laser polymerization

et al. 2017

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The radical propagation kinetics of vinyl acetate (VAc) in pulsed laser polymerization (PLP) is studied by combining ab initio calculated rate coefficients for propagation of head, tail and mid-chain radicals, and backbiting reactions with kinetic Monte Carlo modeling of PLP spectra. The intriguing laser pulse frequency dependency of the propagation kinetics is shown to be mainly caused by the formation of stabilized mid-chain radicals via backbiting of tail radicals, originating from head-to-head propagation. These mid-chain radicals are approximately 35 times less reactive towards propagation at 323 K which, in agreement with experimental observations, results in a 15% increase of the observed propagation rate coefficient if the laser pulse frequency is increased from low (25-100 s −1

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“…In this connection, it is notably recalled that the free-radical polymerizations of ethylene, [32][33][34][35][36][37] vinyl chloride, 38,39 vinyl acetate, [40][41][42][43] and acrylate esters [44][45][46][47][48][49] are governed by the polymerization mechanism involving mid-chain radical formed through backbiting hydrogen abstraction of growing polymer radical. …”

Section: Does Addition-fragmentation Chain Transfer Occur Significantly?mentioning

confidence: 99%

Reassessment of Free-Radical Polymerization Mechanism of Allyl Acetate Based on End-Group Determination of Resulting Oligomers by MALDI-TOF-MS Spectrometry

et al. 2009

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Microstructures in poly(vinyl alcohol-co-crotonic acid) studied by proton-NMR and carbon-13-NMR

Cited by 28 publications

References 2 publications

Mn2(CO)10-Induced RAFT Polymerization of Vinyl Acetate, Methyl Acrylate, and Styrene

Mn2(CO)10-Induced RAFT Polymerization of Vinyl Acetate, Methyl Acrylate, and Styrene

Ab initio based kinetic Monte Carlo analysis to unravel the propagation kinetics in vinyl acetate pulsed laser polymerization

Reassessment of Free-Radical Polymerization Mechanism of Allyl Acetate Based on End-Group Determination of Resulting Oligomers by MALDI-TOF-MS Spectrometry

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