RAFT Grafting Polymerization of Styrene on the Surface of SiO2

Double bonds were immobilized onto nanoSiO2 via hydrolyzing alkoxysilane moiety of γ-methacryl trimethoxysilane for condensation with hydroxide groups from nanoSiO2. RAFT grafting polymerization of styrene from nanoSiO2 was carried out from the immobilized double bonds, in which azobisisobutyronitrile was used as initiator, 2-cyanoprop2-yldithiobenzoate, benzyl dithiobenzoate, benzyl dithiopivalate, 1,2,4-triazolyl-1-carbodithioic acid benzyl ester were used as RAFT agent, respectively. Results showed that RAFT grafting polymerization rate of styrene from SiO2 was decided by Z group of RAFT agent. Grafting polymerization of styrene from SiO2 mediated by benzyl dithiopivalate exhibited the highest grafting polymerization rate.