Explanation

A class of macromolecule whose crystalline structure can be transformed from an anisotropic crystal to an isotropic liquid after being melted by heat or dissolved by solvent. According to the formation conditions of liquid crystal, it can be divided into lyotmpic liquid crystals, thermotropic liquid crystals, inductive liquid crystal and fluidic liquid crystal; According to the different molecular arrangement and order, it can be divided into nematic liquid crystal, smectic liquid crystal, chiral nematic liquid crystal; According to the location of liquid crystal units, they can be classified into main chain liquid crystals and side chain liquid crystals. Compared with small molecule liquid crystal, macromolecule liquid crystal has the following characteristics: thermal stability is greatly improved, thermotropic liquid crystals macromolecule has a larger phase zone temperature, viscosity is large, and flow behavior is significantly different from general solution; It is mainly used to manufacture fibers with high tensile strength and modulus, composite materials, information storage media, precision temperature indicating materials, liquid crystal display materials, biological functional materials, etc. I Main varieties: lyotmpic liquid crystals include aromatic polyamide, polyamide hydrazide, polybenzothiazole, cellulose, etc; thermotropic liquid crystals include liquid crystal aromatic polyester, etc.

Classification