Bisacylphosphine oxides as bifunctional photoinitiators for block copolymer synthesis

Abstract

Block copolymers of styrene (St) and methyl methacrylate (MMA) were prepared via a two-step procedure by using bisacylphosphine oxide (BAPO) as photoinitiator. Photolysis of BAPO at λ = 420 nm in the presence of St yielded polymers with monoacylphosphine oxide terminal groups. Subsequent irradiation of the polymers in the presence of MMA at λ = 380 nm produced block copolymers. Block copolymer formation was evidenced by spectral measurements and GPC analysis.