Alkyne-functional homopolymers and block copolymers through nitroxide-mediated free radical polymerization of 4-(phenylethynyl)styrene

Nitroxide-mediated polymerization of the alkyne-functional monomer 4-(phenylethynyl)styrene allows the preparation of homopolymers and block copolymers with narrow molecular weight distributions. At higher conversions, side reactions, including addition of mediating nitroxides to alkyne groups, lead to broader molecular weight distributions. While differential scanning calorimetry suggests that poly((4-phenylethynyl)styrene) blocks of moderate molecular weight have a fair degree of miscibility with polystyrene, reaction of the pendant alkyne groups of these copolymers with dicobalt octacarbonyl leads to microphase-segregated cobalt-functional materials.