Explanation

Linear, crystalline, saturated polyester, is one of engineering plastics. It can be obtained by ester exchange reaction between dimethyl phthalate and 1,4-butanediol, followed by condensation polymerization at high temperature and high vacuum, or by direct esterification of terephthalic acid and butanediol, followed by condensation polymerization. After meltphase polycondensation, solid state polycondensation can be further carried out to improve the molecular weight of polymer. Its density ranges from 1.31 to 1.55 g/cm 3 The glass transition temperature is about 30 ° C, the melting temperature is between 223 ° C and 232 ° C, and the crystallinity can reach 40%. Notch impact strength is 2.1 to 2.6 kJ/m 2， The tensile strength is 56 to 60 MPa, and the bending strength is 84 to 90 MPa. The heat deflection temperature of unreinforced PBT is between 55 and 60 ° C, while the heat deflection temperature (load 13.6 kgf/cm) of glass fiber reinforced PBT 2） Up to 180 to 205 ° C (1 kgf/cm 2 Approximately equal to 98.0665 kPa). PBT has good dimensional stability, its water absorption is less than 0.3%, and it has the performance of resistance to aromatic hydrocarbons, alcohols, ethers, and chlorinated hydrocarbons. At the same time, it has fatigue resistance, stable dielectric properties, and small changes in dielectric properties under high temperature and high humidity conditions. PBT is mainly used to produce engineering plastics, and a small amount is used for fiber products. It is widely used in fields such as electronics and electronics, automotive manufacturing, machinery, instrumentation, household appliances, and light industrial products.

Classification