Microstructure determination of 2-hydroxy ethyl methacrylate and methyl acrylate copolymers by NMR spectroscopy

Copolymers of 2-Hydroxy ethyl methacrylate and methyl acrylate (H/M) of different compositions were synthesized by free radical bulk polymerization using azobisisobutyronitrile (AIBN) as an initiator under nitrogen atmosphere. The copolymers compositions were calculated from H-1 NMR spectra. The reactivity ratios for H/M copolymers obtained from a linear Kelen-Tudos method (KT) and non-linear error-in-variables method (EVM) are r(H) = 3.31 +/- 0.08, r(M) = 0.23 +/- 0.00 and r(H) = 3.32, r(M) = 0.23, respectively. The complete spectral assignment of methine, methylene, methyl and carbonyl carbon regions in terms of compositional and configurational sequences of H/M copolymers was done with the help of C-13 {H-1} NMR, distortionless enhancement by polarization transfer (DEPT), two-dimensional heteronuclear single quantum coherence (HSQC) along with total correlated spectroscopy (TOCSY). Further, the assignments of carbonyl region were made with the help of heteronuclear multiple bond coherence (HMBC) spectrum. (c) 2006 Elsevier B.V. All rights reserved.