MPO改性PTT共聚酯熔融结晶行为研究

Study on Melting and Crystallization Behavior of PTT Copolyesters Modified by MPO

采用直接酯化熔融缩聚法合成了一系列不同含量的2-甲基-1,3-丙二醇(MPO)改性的共聚酯,并采用差示扫描量热仪(DSC)研究了其熔融结晶行为。结果表明,MPO的加入使聚对苯二甲酸丙二醇酯(PTT)熔点和结晶温度降低,加入摩尔比为20%的MPO可以使PTT熔点由原来的226.64℃降至201.78℃,加入摩尔比为10%的MPO可以使PTT结晶温度由原来的159.01℃降至137.50℃,同时使半结晶时间(t1/2)增大;随降温速率的提高,各样品的结晶温度向低温方向移动,放热峰由窄变宽,t1/2变小;不同降温速率下,改性共聚酯的结晶速率常数(Zc)比纯PTT的Zc减小。

PTT was copolymerizing modified with 2-methy-1,3-propanediol （MPO） through melt esterifieation, and the melt crystallization behavior was studied by differential scanning calorimetry （DSC）. It was found that when the MPO content was 20 ~, the melting point of PTT decreased from 226.64 to 201.78 ~C ; when the MPO contents was 10 ~, the crystallization temperature was decreased from 159.0 to 137. 5℃, and the half crystallization time （t1/2） increased. With increasing cooling rate, the crystallization temperature of each sample moved to lower temperature and the exothermie peak changed from narrow to wide and t1/2 decreased. In addition, the non- isothermal crystallization behavior of the modified PTT was studied with Jeziorny method, and it was found that the crystallization rate constant （Zc） of the PTT became lower than neat PTT, which indicated that the crystallization ability of PTT after adding MPO became poorer.