Nitroxide-mediated ?living? free radical synthesis of novel rod-coil diblock copolymers with polystyrene and mesogen-jacketed liquid-crystal polymer segments
✍ Scribed by Wan, Xinhua; Tu, Yingfeng; Zhang, Dong; Zhou, Qifeng
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 97 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0959-8103
No coin nor oath required. For personal study only.
✦ Synopsis
The synthesis of rod±coil diblock copolymers with narrow polydispersity was achieved for the ®rst time by TEMPO-mediated `living' free radical polymerization of styrene and 2,5-bis[(4methoxyphenyl)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 con®rmed by GPC, 1 H and 13 C 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.