Free- and reversible deactivation radical (co)polymerization of isobutylene in water under environmentally benign conditions

Abstract

The synthesis of a linear polyisobutylene is achieved for the first time by free radical polymerization. The reaction was performed in environmentally friendly conditions, i.e., in an aqueous medium using cyclodextrin solubilizer, around room temperature. This mild and straightforward radical polymerization resulted in a predominantly linear polymer with low dispersity. Isobutylene was also copolymerized with acrylamide via this cyclodextrin assisted aqueous free-radical polymerization, leading to new poly(isobutylene-co-acrylamide) amphiphilic copolymers. The feed composition of copolymerization had a huge effect on the composition and, therefore, the resulting copolymer's solubility. Reversible addition-fragmentation chain transfer radical polymerization (RAFT) of isobutylene was also carried out using a PEG-based symmetrical macro chain transfer agent. Poly(PEG-b-isobutylene-b-PEG) block-copolymer was formed in this one-pot reaction. This novel polymerization method for isobutylene opens new, environmentally benign routes to produce novel copolymers for various applications.