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Microstructure analysis of N ‐vinyl‐2‐pyrrolidone/vinyl acetate copolymers by NMR spectroscopy
Author(s) -
Brar Ajaib S,
Kumar Rajeev
Publication year - 2002
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.901
Subject(s) - copolymer , vinyl acetate , homonuclear molecule , reactivity (psychology) , spectroscopy , polymer chemistry , heteronuclear molecule , nuclear magnetic resonance spectroscopy , materials science , microstructure , chemistry , analytical chemistry (journal) , crystallography , organic chemistry , polymer , molecule , physics , medicine , alternative medicine , pathology , quantum mechanics
N ‐Vinyl‐2‐pyrrolidone ( V ) and vinyl acetate ( A ) copolymers of different compositions were synthesized by free radical bulk polymerization. The copolymer composition of these copolymers was determined using quantitative 13 C{ 1 H} NMR spectra. The reactivity ratios for these comonomers were determined using the Kelen–Tudos (KT) and non‐linear least‐square error‐in‐variable (EVM) methods. The reactivity ratios calculated from the KT and EVM methods are r V = 2.86 ± 0.16, r A = 0.36 ± 0.09 and r V = 2.56, r A = 0.33, respectively. 1 H, 13 C{ 1 H} and 1 H– 13 C heteronuclear shift correlation spectroscopy (HSQC) and 1 H– 1 H homonuclear total correlation spectroscopy (TOCSY) were used for the compositional and configurational assignments of V/A copolymers. The 13 C distortionless enhancement by polarization transfer (DEPT) technique was used to resolve the methine, methylene and methyl resonance signals in the V/A copolymers. © 2002 Society of Chemical Industry