不同温度熔融条件下聚对苯二甲酸乙二醇酯的结晶与熔融行为

分别采用低黏度和高黏度的聚对苯二甲酸乙二醇酯(PET)树脂切片,利用差示扫描量热分析(DSC)的方法研究不同的熔融温度条件对PET结晶行为和熔融行为的影响。结果表明:和高黏度PET相比,低黏度PET的结晶过程对熔融温度的变化极其敏感,不同熔融温度将对它的结晶行为与熔融行为产生显著的影响;在同等条件下,低黏度PET结晶速率快且易生成稳定的结晶结构,其稳定结晶的熔融温度要比高黏度PET高数度;总体上,采用较低的熔融温度有利于提高PET结晶温度和结晶速率,而采用较高的熔融温度有利于提高PET结晶的稳定性。

Effects of the Heating Temperatures on Crystallization and Melting Behavior of Poly( ethylene terephthalate) s

The effects of different heating temperatures on the crystallization and melting behaviors of two poly(ethylene terephthalate)s with different intrinsic viscosities was investigated by using differential scanning calorimetry(DSC).The results showed that in contrast to the high viscosity PET,the crystallization process of the low viscosity PET was much more sensitive to the change in the heating temperature,and a change in the heating temperature had significant impact on both crystallization and melting behavior.Under identical conditions,the crystalli-zation rate of low viscosity PET was faster and tended to form stable crystal structure,and the melting temperature of the stable crystals was several degrees higher than that of the high viscosity PET.In general,a lower heating temperature favored the increases in the crystallization temperature and crystallization rate of PET,while a higher heating temperature favored the increase in the stability of the PET crystals.