Synthesis of styrene/methyl methacrylate copolymers by atom transfer radical polymerization: 2D NMR investigations

Abstract

AbstractCopolymers of styrene and methyl methacrylate were synthesized by atom transfer radical polymerization using methyl 2‐bromopropionate as initiator and CuBr/N,N,N′,N′,N″‐pentamethyldiethylenetriamine as catalyst. Molecular weight distributions were determined by gel permeation chromatography. The composition of the copolymer was determined by 1H NMR. The comonomer reactivity ratios, determined by both Kelen–Tudos and nonlinear error‐in‐variables methods, were rS = 0.64 ± 0.08, rM = 0.63 ± 0.08 and rS = 0.66, rM = 0.65, respectively. The α‐methyl and carbonyl carbon resonances were found to be compositionally and configurationally sensitive. Complete spectral assignments of the 1H and 13C NMR spectra of the copolymers were done by distortionless enhancement by polarization transfer and two‐dimensional NMR techniques such as heteronuclear single quantum coherence and heteronuclear multiple quantum coherence. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2076–2085, 2006