Nitroxide‐mediated ‘living’ free radical synthesis of novel rod–coil diblock copolymers with polystyrene and mesogen‐jacketed liquid‐crystal polymer segments

Abstract

The synthesis of rod–coil diblock copolymers with narrow polydispersity was achieved for the first time by TEMPO-mediated ‘living’ free radical polymerization of styrene and 2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene. The block architecture of the two diblock copolymers thus prepared, MPCS-block-St (5400/2400) and MPCS-block-St (10 800/8700), was confirmed by GPC, 1H and 13C NMR and DSC studies. The liquid-crystalline behaviour of the copolymers was studied by DSC and polarized optical microscope. It was observed that both copolymers showed two distinct glass transitions, corresponding to polystyrene and poly(-2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene). Above the glass transition temperature of rigid block, liquid-crystalline phase was formed. The clearing point of the phase is higher than the polymer decomposition temperature. © 2000 Society of Chemical Industry