钾离子对丁腈橡胶在含砂介质中摩擦磨损行为的影响

摘要

利用自行设计的往复式磨损试验机研究丁腈橡胶在含砂KCl溶液和蒸馏水2种介质中的摩擦磨损行为,并利用场发射扫描电镜对橡胶磨痕的表面形貌及元素含量进行分析.结果表明:在2种介质中,随着载荷的增加,丁腈橡胶的摩擦因数降低而磨损量增加,但在含砂的KCl溶液介质中摩擦因数和磨损量的变化程度均高于在含砂蒸馏水介质中.丁腈橡胶在含砂KCl溶液的磨损机制为腐蚀磨损以及磨粒滑动侵蚀,在含砂蒸馏水中的磨损机制为湿磨粒磨损.K+使得丁腈橡胶表层及亚表层分子链更容易断裂,进而生成了分子量和分散性都低的产物和小分子单体,以及新的支联网状结构.%Tribological behaviors of nitrile rubber(NBR) in two kinds of medium,KCl solution with sand and distilled water with sand were investigated by the self-designed reciprocating wear tester,and the morphology and dement content of NBR worn surface were analyzed by the field emission scanning electron microscope.The results show that,with the increasing of load,the friction coefficient of NBR is decreased and the wear loss is increased in two kinds of medium,but the variation degree of the friction coefficient and wear loss in the medium of KCl solution containing sand is higher than in the medium of distilled water containing sand.The wear mechanism of NBR in KCl solution with sand is corrosive wear and abrasive sliding erosion,and the wear mechanism in distilled water with sand is wet abrasive wear.The molecular chains of surface and subsurface of NBR are more prone to be ruptured under the action of K+,which leads to the generation of low molecular monomers with low molecular weight and dispersion,as well as the new branch network structure.