Synthesis and Characterization of Well-Defined Mid-Chain Functional Macrophotoinitiators of Polystyrene by Combination of ATRP and “Click” Chemistry

摘要

A combination of ATRP and “click” chemistry is employed for efficient preparation of a novel well-defined mid-chain functional macrophotoinitiator of polystyrene. Bromo-terminated polystyrene (PSt-Br) is prepared by ATRP of styrene using a methyl-2-bromopropanoate initiator with CuBr/PMDETA. Subsequently, PSt-Br is converted to PSt-N₃ by a simple nucleophilic substitution reaction. A dialkyne-functionalized photoinitiator (alkyne-PI-alkyne) is synthesized using a dihydroxy-functional photoinitiator and propargyl bromide. Then the “click” reaction between PSt-N₃ and alkyne-PI-alkyne is performed by Cu(I) catalysis. Spectroscopic studies reveal that low-polydispersity polystyrene with the desired photoinitiator functionality in the middle of the chain (PSt-PI-PSt) is obtained.