Facile and cost-effective branched acrylic copolymers from multifunctional comonomers and multifunctional chain transfer agents

Abstract

Branched acrylic copolymers were synthesised via facile conventional free-radical polymerisations taken to high conversion. Methyl methacrylate was copolymerised with various multifunctional comonomers using a range of different chain transfer agents to inhibit gelation. A variety of soluble, branched polymer architectures have been synthesised using multifunctional comonomers containing 2–6 acrylate functional groups and chain transfer agents containing 1–8 thiol functional groups. Independent of polymer composition, all copolymers were proven to be branched with broader molecular weight distributions compared to linear analogues. The molecular weights, Mark–Houwink constants and T_g's all changed systematically depending on the functionality of multifunctional monomer and chain transfer agent used. The results from this pragmatic modification of conventional radical polymerisation are placed in the context of controlled radical polymerisation methodologies.