模压成型工艺对PE-UHMW结晶度和耐磨性能的影响

摘要

Ultra high molecular weight polyethylene (PE-UHMW) was compression-molded through changing compression moulding temperature, time and cooling cycle with initial pressure of 3.6 MPa. The effects of the compression molding process on the crystallinity and wear resistance of PE-UHMW was studied. The results show that under different compression molding time or temperature,there is not an ideal corresponding relationship between the changes of crystallinity and wear resistance. But it is summarized from the results as a whole that the crystallinity and wear resistance all decrease due to the increased compression molding time or temperature. When the compression molding time is 30 min and the temperature is 230℃,the best wear resistance of PE-UHMW is achieved. Different cooling cycles have a little effect on the crystallinity of PE-UHMW,but have great influence on the wear resistance. PE-UHMW with optimun wear resistance can be obtained by adopting a slower cooling rate and keeping the crystallization temperature of PE-UHMW for 30 min in the cooling process.%在3.6 MPa的初始模压压力下，分别改变模压温度、模压时间和冷却方式对超高分子量聚乙烯(PE–UHMW)进行了模压成型，研究了PE–UHMW模压成型工艺对其结晶度和耐磨性能的影响。结果表明，在不同的模压温度或模压时间下，PE–UHMW结晶度与耐磨性能的变化没有理想的对应关系；但从整体结果可以得出，较高模压温度或较长的模压时间会导致PE–UHMW结晶度降低，耐磨性能变差。模压温度为230℃、模压时间为30 min时， PE–UHMW的耐磨性能最好。不同冷却方式对PE–UHMW结晶度的影响较小，对耐磨性能的影响较大。采用较低的冷却速率并在PE–UHMW结晶温度下保温30 min，可以得到耐磨性能优异的PE–UHMW。