摘要
应用差示扫描量热法 (DSC)和广角 X射线衍射 (WAXD)研究了低温干燥高温固相缩聚 PET的熔融行为和结晶结构。根据 DSC结果分析了固相缩聚反应温度和时间对熔融双峰的影响 ,得到熔点与固相缩聚反应温度有线性关系 ,熔点和结晶度与固相缩聚反应时间的对数呈线性关系。利用 WAXD研究了固相缩聚反应温度和时间对表观晶粒尺寸的影响。结果说明低温结晶时形成的不完善晶体在固相缩聚过程中发生部分熔融、重结晶 ,结晶结构趋于完善以及更稳定新晶体的形成 ,促使 PET熔点升高 ,结晶度增加。
The melting behaviour of poly(ethylene terephthalate) prepared by solid state polycondensation(SSP) has been investigated using differential scanning calorimetry and wide angel X ray diffraction(WAXD). The effects of SSP reaction temperature and time on dual melting endotherms in the DSC thermograms of PET have been examined. It is showed that a linear relation of lower temperature endotherm peak of PET, T ml , with SSP reaction temperature holds, and that T ml and crystallinity increase almost linearly with the logarithm of reaction time. In addition, the influences of SSP reaction temperature and time on apparent crystalline size have been studied by means of WAXD. The results indicate that the imperfect crystallites formed at lower crystallization temperature undergo a continuous perfection process as a result of partial melting and recrystallization during SSP, in consequence, the perfection of crystalline sturcture and the formation of new stable crystallites during SSP increase the melting point and crystallinity of PET.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2000年第4期162-164,167,共4页
Polymer Materials Science & Engineering
基金
华东理工大学联合化学反应工程研究所固定床国家重点实验室开放基金资助课题
