Physically Controlled Radical Polymerization of Vaporized Vinyl Monomers on Surfaces. Synthesis of Block Copolymers of Methyl Methacrylate and Styrene with a Conventional Free Radical Initiator

Abstract

Physically controlled radical polymerization of vinyl monomers with conventional free radical initiators was achieved in the presence of monomer vapors on solid substrate surfaces. The polymerization of methyl methacrylate (MMA) and styrene (St) by 2,2‘-azobis(isobutyronitrile) (AIBN) on substrate surfaces resulted in the deposition of high molecular weight polymers, forming a rough surface morphology in such forms of aggregated particles. The proportional relationship between the number-average molecular weight and polymer yield was successfully obtained, and the consecutive copolymerization of MMA and St produced a block copolymer, poly(MMA-b-St). These results support the living nature of the free radical polymerization on surfaces in the presence of monomer vapors. The SEM observations of the deposits revealed that the polymerization proceeded with a continuous polymer deposition taking place at points where the active species were immobilized, reflecting a predesigned pattern on the substrate surface.