超高分子量聚乙烯对聚酰胺摩擦磨损行为的影响

采用双螺杆挤出机制备聚酰胺/超高分子量聚乙烯(PA66/UHMWPE)和聚酰胺/超高分子量聚乙烯/马来酸酐接枝高密度聚乙烯(PA66/UHMWPE/MAH-g-HDPE)共混物,采用傅立叶转换红外光谱仪分析共混体系的结构,同时评价其机械性能及摩擦磨损性能.结果表明:加入MAH-g-HDPE相容剂可以使共混体系的相容性得到改善,提高共混物的机械性能;具有平整分子结构的UHMWPE有利于改善PA66的摩擦磨损性能,当摩擦偶件的转移层达到饱和状态后,共混物的耐磨性与其力学性能相关;共混物在摩擦过程中表现出严重的塑性变形和粘着磨损,但在共混体系的摩擦过程中,对摩擦磨损性能起主要作用的是受热软化的UHMWPE在磨损表面形成低剪切强度的界面层,从而使得PA66的摩擦磨损性能明显改善.

Influence of Ultra High Molecule Weight Polyethene on Tribological Behavior of Polyamide

Blends of PA66/UHMWPE and PA66/UHMWPE/MAH-g-HDPE were prepared by co-twin screw extrusion. FT-IR analysis, mechanical and tribological tests show that the mechanical strength of the blends were improved by adding MAH-g-HDPE. UHMWPE has regular molecule chain and lower shear strength, so it improved the tribological property of PA66. When the amount of the transferring layer reached a certain value, severe plastic distortion and adhesion wear occurred, and wear resistance of the blends was related to the mechanical property of the blends. Worn microstructure changes with addition of compatibilizer. Soft UHMWPE produced from friction heating has low shear strength, and it improves the tribological property of PA66 during the friction course.