Synthesis of methyl methacrylate star-branched polymer with divinylbenzene as a linking agent via controlled/living photopolymerization

HTEMPO-functionalized central cores were formed with divinylbenzene in ＇＇core first＇＇ method,and the four or five arms star polymers were built via controlled/living free radical photopolymerization.The four arms star polymers were also prepared with controlled/living free radical photopolymerization in ＇＇arm first＇＇ method.The resulting polymers had been confirmed by GPC and 1 H NMR.It showed that the star polymers had low polydispersities and molecular weight（M n） with the 85,000-560,000 g/mol range.