22575-25-3Relevant articles and documents
Cross-linked liquid crystalline polybenzoxazines bearing cholesterol-based mesogen side groups
Liu, Ying,Chen, Jiming,Qi, Yongxin,Gao, Sheng,Balaji, Krishnasamy,Zhang, Yaoheng,Xue, Qingbin,Lu, Zaijun
, p. 252 - 260 (2018)
A cross-linked liquid crystalline polybenzoxazine [poly(BA-ac)] was synthesized for the first time from a novel bifunctional benzoxazine monomer (BA-ac) containing cholesterol-based mesogens. The monomer was synthesized using cholesteryl 4-aminobenzoate, bisphenol-A, and paraformaldehyde as raw materials via Mannich reaction. Subsequently, the cross-linked polybenzoxazine bearing cholesterol-based mesogen side groups was obtained through thermally induced ring-opening polymerization of the benzoxazine ring. The study results show that BA-ac is a monotropic smectic C liquid crystal, and poly(BA-ac) contains a smectic C phase structure. The formation of the liquid crystalline structure of poly(BA-ac) is mainly caused by the strong ability of cholesterol-based mesogen to form liquid crystals and its position on the side group of the cross-linked network. Due to the existence of a liquid crystal structure, poly(BA-ac) has high thermal conductivity. Its coefficient of thermal diffusivity is 31% higher than that of a traditional polybenzoxazine poly(BA-a). Poly(BA-ac) also has high heat-resistance. Its glass transition temperature, 5% and 10% weight loss temperatures are 175 °C, 306 °C, and 321 °C, respectively.
A liquid-crystalline poly(iminomethylene) with cholesterol-containing pendant groups
Walree, C. A. van,Pol, J. F. van der,Zwikker, J. W.
, p. 561 - 565 (2007/10/02)
Two poly(iminomethylenes) with cholesterol-containing pendant groups were synthesized.Using an aliphatic spacer, a liquid-crystalline polymer was obtained, with equal amounts of right- and left-handed helices.With phenylene as bridging group, only oligomers resulted, probably for steric reasons.Some novel liquid-crystalline esters of cholesterol are also presented.
