基于对羟基苯丙酸的生物基液晶共聚酯纤维的合成与性能

针对常规生物基纤维力学性能与耐热性不足的问题,以6-羟基-2-萘甲酸、对羟基苯甲酸和对羟基苯丙酸(HPPA)为原料,采用一锅熔融聚合法合成了生物基液晶共聚酯,并通过熔融纺丝制备得到初生纤维,对共聚酯及其初生纤维的结构与性能进行研究。结果表明:制备得到的生物基液晶共聚酯为向列型液晶,其熔点在200 ℃左右,并随着HPPA添加量的增加而降低,而高HPPA添加量会导致共聚酯熔融行为不明显,不利于结晶;共聚酯具有良好的热稳定性,其质量损失5%时对应的温度高于370 ℃,在700 ℃时的残炭率大于30%;共聚酯初生纤维表面光滑均匀,断面具有明显的原纤结构,力学性能较好,并与HPPA的添加量呈负相关关系。

Synthesis and properties of bio-based liquid crystal copolyester fiber based on p-hydroxyphenyl propionic acid

In order to improve the mechanical property and thermal stability of bio-based polymers,the bio-based liquid crystal copolyester derived from 6-hydroxy-2-naphthenic acid,p-hydroxybenzoic acid and p-hydroxyphenyl propionic acid(HPPA)were studied and successfully synthesized via the one-pot melt polymerization method,and the structures and properties of the spun fibers from the bio-based liquid crystal copolyesters were prepared by melt spinning.The results show that the prepared bio-based liquid crystal copolyester is a nematic liquid crystal polymer.Its melting point is around 200℃,and it decreases with the increase of HPPA monomer content.High content of HPPA leads to weak melting behavior,which is not conducive to crystallization.The copolyesters show good thermal stability and high char yield,and the temperature corresponded to 5%weight loss and char yield at 700℃are above 370℃and 30%,respectively.The surface of the as spun copolyester fiber is smooth and uniform,the cross section has an obvious fibrillar structure.The fibers have good mechanical properties,which are negatively related to the content of HPPA.