RAFT Polymerization of MMA in the Channels of Different Mesoporous Materials

Abstract

Reversible addition fragmentation transfer (RAFT) polymerization is of key significance for its suitability for most monomer and well-studied reaction mechanism. Herein, a serial of mesoporous silica (MS) materials, including rod-liked and spherical SBA-15, spherical MCM-41, and MCM-48, were successfully synthesized and modified by silane coupling agent γ-aminopropyltriethoxysilane (KH550). The modified MS was utilized as a microreactor for reversible addition–fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) using a xanthate as a chain transfer agent and AIBN as an initiator. Note that modified MS had lower specific surface area and pore volume while maintained the original morphological structure. Owing to the confinement effects, poly(methyl methacrylate) (PMMA) prepared from internal mesoporous channels featured with higher molecule weight and initial thermal decomposition temperature than these from conventional RAFT polymerization. More importantly, the PMMA obtained from the spherical SBA-15 and modified MCM-48 exhibited the highest molecule weight. This work provided a novel approach to design of polymer microstructure for a wider application, such as in drug release.