Investigation of eATRP for a Carboxylic‐Acid‐Functionalized Ionic Liquid Monomer

Abstract

AbstractElectrochemically mediated atom transfer radical polymerization (eATRP) is a promising technique for precise control over polymer molecular weights (MWs), molecular weight distribution (Đ), and complex architectures under low concentrations of copper‐based ATRP catalysts. Herein, eATRP of ionic liquid monomer (ILM), 1‐vinyl‐3‐propionate imidazolium tetrafluoroborate (VPI+BF4−), containing carboxylic acid groups is inquired in aqueous media. In the polymerization process of water‐soluble VPI+BF4−, the protonation and dissociation of catalysts have great influence on the polymerization reaction. Various polymerization parameters, including applied potential (Eapp), pH, degree of polymerization (DP) (from 100 to 300), and the catalyst concentration (from 5 × 10−4 to 1.5 × 10−3 m) are examined. Under certain polymerization conditions, poly(ionic liquids) (PILs) with a well‐controlled MWs and narrow Đ are obtained. The controlled/living property of the polymerization process is reflected by the linear first‐order kinetics, linear increase of MWs with monomer conversion, and the probability of complete reactivation of the polymerization by repetitively altering the Eapp values. This work provides a new perspective for the precise synthesis of PIL‐based block copolymers with adjustable properties; meanwhile, the eATRP of monomer containing carboxylic acid groups is expected to develop functional materials with pH responsiveness and biocompatibility.