聚对苯二甲酸丁二醇酯的固相缩聚

分子量对聚对苯二甲酸丁二醇酯 (PBT)的性能有直接影响 ,高分子量PBT通常经固相缩聚的方法获得。本文对PBT固相缩聚的机理、影响因素及产物的结晶和熔融性能进行了全面介绍

SOLID-STATE POLYCONDENSATION OF POLYBUTYLENE TEREPHTHALATE

When polybutylene terephthalate(PBT)is used as engineering plastic materials,the molecular weight plays an important role in order to reach the desired properties.Solid-state polycondensation(SSP)processes,for preparing particular high molecular weight PBT,are carried out by heating the low molecular weight prepolymers in the form of chips in a stream of gas or under vacuum at a temperature above the polymer glass transition but below the melting point.The SSP rate may depend on chemical or physical processes or both,being determined by the slow process.The main factors that affect SSP include reaction temperature and time,particle size,initial molecular weight,number and type of chain end groups,catalyst empolyed,crystallinity,and the technique used to remove by-products.The SSP process has a significant influence on the melting behaviors and the crystalline structure of the polymer.;