新型含磷热致液晶共聚酯的合成与表征

Synthesis and characterization of novel thermotropic liquid crystal copolyester containing phosphorus

采用溶液法合成了一种新型含磷热致液晶共聚酯,使液晶共聚酯的主链上含有介晶单元,侧基上含有阻燃元素磷。利用红外光谱方法对合成的共聚酯的结构进行了分析,利用乌氏黏度计对共聚酯的特性黏度进行了测定,并对共聚酯进行液晶结构分析及广角X射线衍射(WAXD)、热失重分析(TG)等测试。结果表明,共聚酯具有热致液晶性,其液晶织构为向列型,结晶性较高,结晶结构规整;所合成的共聚酯的清亮点高于其分解温度,说明合成的共聚酯有较宽的液晶态温度范围,这对共聚酯的成型加工非常有利;利用含磷酚类物质DOPO-QO合成的液晶共聚酯,具有很好的热稳定性,失重5%时温度达220℃,热分解残余量可达32.5%。

Novel thermotropic liquid crystal copolyester containing phosphorus was synthesized by solution.As a result,the main chain of liquid crystal copolymerization contained mesomorphis,and the side chain contained flame retardant elements phosphorus.The structures and properties of copolyesters were investigated by IR,hot-stage polarizing optical microscope,WAXD and TG.The results showed that the copolyester was thermotropic,and had nematic liquid crystal texture with high crystallinity and neat crystal structures.The clearing temperature of composite copolyester was higher than its decomposition temperature,demonstrating that the composites had a wide range of temperature of nematic state,which was very favorable to molding processing of the copolyester.The synthetic liquid crystal copolymerization using the phenolics contains phosphorus DOPO-QO had a good thermal stability.When weight loss was less than 5%,the temperature was more than 220 ℃ and the char yield was 32.5%.