Synthesis of Silica Particles Grafted with Well-Defined Living Polymeric Chains by Combination of RAFT Polymerization and Coupling Reaction

Abstract

A combinatorial approach based on reversible addition−fragmentation chain transfer (RAFT) polymerization and coupling reaction was used to prepare well-defined silica−polymer hybrids. Chain-end-functionalized homopolymers were synthesized by RAFT polymerization of vinyl monomers such as methyl acrylate, butyl acrylate, N,N-dimethylacrylamide, N-isopropylacrylamide, N-acrylomorpholine, methyl methacrylate, and styrene mediated by S-methoxycarbonylphenylmethyl S′-trimethoxysilylpropyltrithiocarbonate in toluene or dioxane at 60 °C, and di-, tri-, and tetrablock copolymers were further synthesized by successive chain extension polymerization. These polymers comprising a trimethoxysilane functionality in the chain end were then grafted to the surface of flash silica by coupling reaction between trimethoxysilane and hydroxyl groups. IR and thermogravimetric analyses results indicated the grafting ratios of polymeric chains on the surface of silica were relatively high. The grafted polymeric chains were cleaved...