Sequence determination of vinyl acetate–methyl acrylate copolymers by NMR spectroscopy

Abstract

SYNOPSISVinyl acetate/methyl acrylate ( V/M) copolymers were prepared by free-radical solution polymerization in benzene. Copolymer compositions were obtained from 'H-NMR spectroscopy. Reactivity ratios for the copolymerization of V with M were calculated using the Kelen-Tudos ( K T ) and the nonlinear error in variables (EVM) methods. The reactivity ratios obtained from the K T and EV methods are rv = 0.04 k 0.03 and rM = 7.28 k 2.88 and rv = 0.04 t 0.01 and rM = 7.28 f 0.37, respectively. The microstructure was obtained in terms of the distribution of V-and M-centered triad sequences from l3C { 'H } -NMR spectra of copolymers. Homonuclear 'H-2D-COSY and 2D-NOESY NMR were used to determine the most probable conformer for the V/M copolymer. The copolymerization behavior of the V/M copolymers as a function of conversion is also reported. 0 1994 John Wiley & Sons, Inc.

Bulk and solution copolymerization of methyl methacrylate and vinyl acetate

“…The reactivity ratios for the butyl acrylate/VAc (BA/VAc) and methyl methacrylate/VAc (MMA/VAc) systems are reported to be r BA = 5.939 and r VAc = 0.0262 for BA/VAc and r MMA = 24.025 and r VAc = 0.0261 for MMA/VAc 2. Similar values are reported for methyl acrylate/VAc,3, 4 butyl methacrylate/VAc,5 and ethyl methacrylate/VAc 6. For all of these systems, these differing reactivity ratios imply that the acrylic monomer is preferred for addition to the growing copolymer chain over the VAc monomer.…”

Copolymers of acrylic acid with 2‐acryloyloxyethyl 2,4‐dichlorophenoxyacetate: Synthesis and herbicide release

“…The situation developed when the monomer reactivity ratios differ greatly from one another has been extensively described for different systems such as copolymerization of vinyl acetate28–33 and vinylpyrrolidone34–44 with meth(acrylic) monomers.…”

Microstructure determination and thermal studies ofn‐acryloylcarbazole/vinyl acetate copolymers

“…Microstructure determination of poly(N-acryloylcarbazole), 25 poly(vinylacetate), 26,27 and N-acryloylcarbazole/methyl methacrylate 28 (A/M) copolymers by NMR has already been reported. Brar et al [29][30][31][32] have reported comonomer sequence and cotacticity of vinylacetate copolymers. To the best of our knowledge, the microstructure and thermal studies of N-acryloylcarbazole/vinyl acetate (A/V) copolymers have not been reported so far.…”