2D NMR studies of acrylonitrile–methyl acrylate copolymers

The microstructure of acrylonitrile–methyl acrylate copolymers prepared by the solution polymerization using 2,2′-azobisisobutyronitrile (AIBN) as free radical initiator was investigated by two-dimensional NMR techniques. 2D-heteronuclear single quantum correlation (HSQC) and the total correlation spectroscopy (TOCSY) have been utilized to resolve the complex 1H NMR spectrum and to establish the compositional and configurational sequences of acrylonitrile–methyl acrylate copolymers. 2D HSQC and TOCSY showed compositional and configurational sensitivity of methine protons of A and M units upto the triad level. Heteronuclear multiple-bond correlation (HMBC) spectroscopy has been used to study carbon (carbonyl/nitrile)–proton coupling. The carbonyl and nitrile carbons showed compositional sensitivity upto the triad level. The values of reactivity ratios were determined by Kelen–Tudos (KT) and non-linear error in variable method (RREVM).