Wholly aromatic liquid crystal polymer and preparation method thereof

Abstract

The invention discloses a wholly aromatic liquid crystal polymer and a preparation method thereof. The wholly aromatic liquid crystal polymer is obtained by the condensation polymerization reaction offour monomers: para-hydroxybenzoic acid, triptycene quinhydrone, terephthalic acid and m-phthalic acid. By introducing a triptycene unit with a space steric effect, the melting temperature of homopolymerizing para-hydroxybenzoic acid is reduced, a nematic liquid crystal polymer with excellent melting processing performance is obtained and the performance of fiber members is good; the triptycene unit is introduced into a rigid chain so as to have double functions of space steric hindrance and a benzene ring substitutional group, thereby increasing the molecule width of the polymer and reducingthe action force among the molecules and a melting point; however, the extension direction of the rigid chain is not changed and therefore, a copolymer still keeps good liquid crystal performance andgood mechanical performance. The thermal melting temperature of the liquid crystal polymer is from 280 DEG C to 370 DEG C and mostly from 290 DEG C to 350 DEG C. The liquid crystal polymer can be widely used for electronic electric appliances and parts and components of other precise equipment.

Description

Technical field: [0001] The invention belongs to a novel fully aromatic thermotropic liquid crystal polymer and a manufacturing method thereof, and relates to a liquid crystal polymer containing a triptycene structural unit with excellent melt processability. Background technique: [0002] Because the melting point of p-hydroxybenzoic acid homopolymer is above the decomposition temperature, it is insoluble, infusible and inprocessable, so its commercialization and use are greatly restricted. Many companies and scientific research institutes use copolymerization technology to improve their melting properties to produce liquid crystal polymers. This liquid crystal polymer is called super engineering plastics, and its performance is unmatched by other engineering plastics. For example, Carborundum Company (US3637595 and US3975487) and Sumitomo of Japan all use p-hydroxybenzoic acid (pHBA), hydroquinone (HQ), terephthalic acid (TA) / isophthalic acid (IPA) and biphenol (BP ) copo...

AI Technical Summary

Problems solved by technology

Although Vectra has been industrialized for more than 20 years, the price of liquid crystal polymers is still high. An important reason is that a few companies such as Celanese monopolize HNA synthesis technology and liquid crystal polymerization technology, resulting in insufficient supply of raw materials.

In order to reduce costs, manufacturers have begun to develop new monomers, such as 4,4'-biphenyl dicarboxylic acid, 4,4'-dihydroxydiphenyl ether, etc. and polyamide, polycarbonate, polyurethane, polyether and other series The monomer used in liquid crystal polymers, but due to reasons such as price and production process, the commercialization prospect is still unclear

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