聚(对苯二甲酸乙二醇酯-co-对苯二甲酸异山梨醇酯)等温结晶行为研究

摘要

以对苯二甲酸(PTA)、乙二醇(EG)、异山梨醇(ISB)为原料,通过直接熔融缩聚法合成聚(对苯二甲酸乙二醇酯-co-对苯二甲酸异山梨醇酯)(PEIT)共聚酯.利用差示扫描量热法(DSC)研究了共聚酯的结晶行为,采用Avrami方程分析了共聚酯的等温结晶动力学.结果表明,PEIT共聚酯结晶行为受共聚组成和结晶温度影响.随着ISB用量的增加或结晶温度的降低,共聚酯半结晶周期t1/2增加、结晶速率变慢;ISB摩尔分数超过20%,共聚酯无法结晶.%Polyesters based on terephthalic acid and different ratios of ethylene glycol and isosorbide units were synthesized from polycondensation of the appropriate of the monomers.The crystallization behavior of poly(ethylene terephthalate-co-isosorbide terephthalate) (PEIT) copolyesters was investigated by means of differential scanning calorimetry (DSC).Isothermal crystallization kinetics of PEIT has been analyzed by the well known Avrami equation.The results revealed that the crystallization behavior of PEIT was affected the crystallization temperature and the composition of copolyesters.Under the same crystallization condition, as the isosorbide content increased or crystallization temperature decreased, the half-time crystallization (t1/2) of the copolyesters prolonged, meanwhile the crystallization speed of the copolyesters was slower.while the content of isosorbide was more than 20% in the glycols, the copolyester cannot be crystallized.