结晶条件对超高分子量聚乙烯熔融再结晶行为的影响

Effect of Crystallization Conditions on Melt Recrystallization Behavior of PE-UHMW

应用常压差示扫描量热（DSC） 仪和高压DSC 仪研究了熔融温度、熔融时间、冷却速率以及压力对不同分子量的超高分子量聚乙烯（PE–UHMW） 熔融再结晶行为的影响.常压DSC 的研究表明,随着熔融温度、熔融时间以及冷却速率的增加,PE–UHMW 的结晶峰值温度（Tc） 逐渐下降.在相同的熔融温度和熔融时间下,PE–UHMW 的Tc随分子量的增加而逐渐增加,但在所研究的冷却速率范围内（2.5～40℃/min）,在相同的冷却速率下,Tc 随分子量的增加变化不大.高压DSC 的研究结果表明,结晶过程中增加压力导致PE–UHMW 的Tc 有所下降,并且结晶峰半峰宽变大.

The melt-recrystallization behavior of ultra-high molecular weight polyethylene (PE–UHMW) with different molecular weight at different crystallization conditions was investigated by differential scanning calorimetry (DSC) and high pressure DSC,from the aspects such as melting temperature,melting time,cooling rate and pressure,respectively. The analysis showed that lower crystallization temperature (Tc) with higher melting temperature,longer melting time and higher cooling rate. TheTc of PE–UHMW increased with the molecular weight under the same melting temperature and melting time,however,in the research range of cooling rate (2.5–40℃/min),theTc little change with the increase of molecular weight under the same cooling rate. Compared with constant pressure,PE–UHMW had lowerTc but bigger half peak breadth at higher pressure.