超高分子量聚乙烯结晶度对生物摩擦学性能的影响

The Biotribological Behavior of Ultra-high Molecular Weight Polyethylene as a Function of Crystallinity

研究了不同结晶度对超高分子量聚乙烯力学和生物摩擦学性能的影响。将超高分子量聚乙烯加热至130℃并保温4h后,分别在液氮中快速冷却和加热炉中缓慢冷却,以此来改变其结晶度。利用差示扫描量热法(DSC)测试了样品的结晶度,并研究了不同结晶度对超高分子量聚乙烯的硬度、小型冲击性能、抗划痕性能和生物摩擦学性能的影响。结果显示,在加热炉中缓慢冷却的试样获得较高的结晶度,而在液氮中快速冷却的试样则具有较低的结晶度,分别为61.9%和53.2%;较高结晶度的超高分子量聚乙烯具有较高的硬度和抗拉强度,较强的抗剪切和抗划痕性能;小牛血清润滑下的往复式摩擦磨损试验结果显示,较高结晶度的超高分子量聚乙烯的摩擦因数和磨损率较低。

The mechanical property and biotribological behavior of ultra-high molecular weight polyethylene （UHM- WPE） were studied as a function of erystallinity. Crystallinity was obtained by heating UHMWPE to 130 ℃ , holding for 4 hours and cooling in liquid nitrogen and in furnace. The percent of crystallinity of the samples was evaluated using differential scanning calorimetry （DSC）. The hardness, small punch test, scratch and biotribologieal behavior of UHMWPE specimen were evaluated as the effect of crystallinity. The results show that a higher degree of crystallinity is obtained by cooling in furnace,a lower degree of crystallinity is obtained by cooling in liquid nitrogen, and the crystallinity is 61.9% and 53.2% respectively. A higher degree of crystallinity in the UHMWPE results in the increase in hardness, tensile strength, shear strength and scratch resistance. Reciprocating-wear tests under the lubrication of bovine calf serum show that an increase in crystallinity results in lower friction coefficient and wear loss.