溶液成膜的温度对聚对苯二甲酸乙二酯结晶度的影响

TEMPERATURE EFFECT ON CRYSTALLINITY DURING SOLUTION CAST FILM OF POLY (ETHYLENE TEREPHTHALATE)

用溶液成膜是制备聚合物薄膜的常用方法之一。但是溶液成膜的条件,如成膜温度,溶液浓度等对半结晶聚合物结晶度的影响研究报道较少。制备聚对苯二甲酸乙二酯(PET)非晶态薄膜通常使用熔融热压其后淬火的方法。由于PET在熔点附近易于降解,在薄膜中产生气泡,因而很难制备较大面积的均一厚度的薄膜。

PET pellets were dissolved in chloroform-trifluoroacetic acid (4.1 vol.). The concentrations of solution were 9 and 12 wt% respectively. A glass plate was inserted into the solution, then taken out and held at different temperature (from room temperature to 100℃) to make the solution cast films of ca. 10μm thick. The absorbance ratio A978/A795 of 973cm-1 and 795cm-1 infrared bands was used to measure the crystallinity of the solution cast PET films. The result shows that the film cast at room temperature was semi-crystalline and the film cast at higher temperature was amorphous.