成核剂对PET/PEN共混体系热降解与结晶形态的影响

用热失重(TGA)、X射线(WAXS)和偏光显微镜(PLM)研究了三种成核剂对聚对苯二甲酸乙二酯/聚萘二甲酸乙二醇酯(PET/PEN)共混体系的热降解行为、结晶行为和形态的影响。结果表明,成核剂的加入,加速了PET/PEN共混物的降解;且DBS1,3:2,4-二(亚苄基)-D山梨醇]对PET/PEN共混物的影响最大,CaCO3对PET/PEN共混物的影响最小;含有DBS的PET/PEN共混物形成了环带球晶,CaCO3与PET/PEN共混物同时结晶,且成核剂的加入使晶体形态更完善。用差减微分法研究了PET/PEN/成核剂共混体系热降解动力学,计算得到了活化能(E)和反应级数(n),计算得到的活化能关系为EPET/PEN>EPET/PEN/DBS>EPET/PEN/CaCO3>EPET/PEN/SB。

Thermal Degradation and Crystal Property of PET/PEN/Nucleating Agent Blend System

The thermogravimetric analysis(TGA) has been used to study the thermo-degradation behavior,the results indicate that the adding of nucleating agent accelerates the degradation of PET/PEN and the effect of DBS to PET/PEN is biggest,the effect of CaCO3 to PET/PEN is least.The activation energy(E) and reaction order(n) were calculated from TGA curves by differential subtract differential method,the E order of them is EPET/PEN>EPET/PEN/DBS>EPET/PEN/CaCO3>EPET/PEN/SB,and the reaction order of them is close;The crystal morphology of PET/PEN/nucleating agent blend system had been analyzed by polarizing microscope(PLM),the results indicate that the four samples can crystallization,and the adding of nucleating agent reduces the size of crystal.