Controlled Free‐Radical Copolymerization of <i>N</i>‐vinyl succinimide and <i>n</i>‐Butyl acrylate via a Reversible Addition–Fragmentation Chain Transfer (RAFT) Technique

Abstract

Abstract Summary : Copolymerization of N‐vinyl succinimide and n ‐butyl acrylate in the presence of dibenzyl trithiocarbonate as a reversible addition‐fragmentation chain transfer agent was investigated. The linear dependence of molecular mass on conversion and low values of polydispersity index confirmed pseudo‐living mechanism of the process. For the first time the soluble copolymers of N‐vinyl succinimide and n ‐butyl acrylate with high composition homogeneity have been synthesized by copolymerization in bulk. The copolymerization kinetics was studied by NMR 1 H spectroscopy; the reactivity ratios were determined: r VSI = 0.11, r BA = 2.54. The copolymer microstructure was estimated; it was shown that in conditions of RAFT polymerization gradient copolymers enriched with BA on the tails of the macromolecule and with VSI in the middle can be obtained. The method of elimination of trithiocarbonate fragment by the reaction with an excess of AIBN was proposed leading to formation of the simplest gradient structure of N‐vinyl succinimide – n ‐butyl acrylate copolymer.