Synthesis of well-defined polystyrene macrophotoinitiators by atom-transfer radical polymerization

Abstract

New mono- and bifunctional atom-transfer radical polymerization (ATRP) initiators were synthesized by the condensation of 2-bromopropanoyl bromide with 2-hydroxy-2-methyl-1-phenyl propan-1-one (HMPP) and 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl propan-1-one (HE-HMPP), respectively and characterized. The ATRP of styrene (St) in bulk at 110 °C by means of these initiators in conjunction with a cuprous complex Cu(I)Br/bipyridine yields polystyrenes with photoactive alkoxy phenylketone groups. Gel permeation chromatography, spectroscopic and photodegradation studies revealed that the initiation efficiency was quantitative and low-polydispersity polystyrenes with photoinitiator functionality in the end or middle of the chain were obtained.