Synthesis of transparent block copolymers consisting of poly(diisopropyl fumarate) and poly(2‐ethylhexyl acrylate) segments by reversible addition‐fragmentation chain transfer polymerization using trithiocarbonates as the chain transfer agents

Abstract

ABSTRACTThe reversible addition‐fragmentation chain transfer polymerization of diisopropyl fumarate (DiPF) was carried out using ethyl 2‐[[(dodecylthio)thioxymethyl]thio]‐2‐methylpropionate (T1) and 1,1′‐(1,2‐ethanediyl) bis[2‐[[(dodecylthio)thioxymethyl]thio]‐2‐methylpropionate] (T2) as the monofunctional and difunctional chain transfer agents (CTAs) to synthesize poly(diisopropyl fumarate) (PDiPF) with a rigid chain conformation. The obtained PDiPF had a well‐controlled molecular weight, molecular weight distribution, and structure of the chain ends. Size exclusion chromatography and NMR measurements revealed an excellent introduction efficiency (84–98%) of the terminal trithiocarbonate group into the polymer chain end. They were available as the monofunctional and difunctional macro‐CTAs to synthesize the AB and ABA block copolymers, respectively. While the well‐controlled block copolymers were solely obtained by the polymerization of 2‐ethylhexyl acrylate as the second monomer in the presence of PDiPF as the macro‐CTA, the block copolymerization of DiPF using poly(2‐ethylhexyl acrylate) as the macro‐CTA failed. The trithiocarbonate group at the chain end was completely removed by the reaction with n‐butylamine and it was valid for the improvement of the coloration and other optical properties of the transparent polymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2584–2594