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以3,3,4’,4’-联苯四甲酸二酐(s-BPDA)、4,4’-二氨基二苯醚(4,4’-ODA)、3,4’-二氨基二苯醚(3,4’-ODA)、4-苯乙炔苯酐(4-PEPA)为前驱体,设计并制备了热固性聚酰亚胺.采用球盘式高温摩擦磨损试验机进行室温(25℃)、100、200、250、300和350℃条件下的滑动摩擦磨损试验.通过表征不同温度磨损后的材料和对偶表面形貌,研究了其高温条件下的摩擦行为和磨损机制.结果表明:随着环境温度的升高,热固性聚酰亚胺的磨损率呈现先升高,后降低再升高的趋势;而摩擦系数却一直降低.这种趋势归结于聚合物接触表面机械性能的改变.不同温度条件下的磨损机理也是不同的,25和100℃条件下的磨损主要为疲劳磨损和磨粒磨损;随着环境温度升高到200℃时,磨损表面部分链段易于剪切,形成一层均匀的转移膜而降低了磨粒磨损;当温度升高至250、300以及350℃时,磨损表面的分子链段运动更加剧烈,在试验载荷持续挤压下,分子链间作用力破坏而剥落,磨损率急剧升高,表现为黏着磨损,并且环境温度越高,磨损率越大.
(4,4’-ODA), 3,4’-diaminobis (4,4’-ODA) and 3,4’-biphenyldicarboxylic acid dianhydride (3,4-ODA), 4-phenylacetylene phthalic anhydride (4-PEPA) as precursors, a thermosetting polyimide was designed and prepared.Using the ball-type high temperature friction and wear testing machine at room temperature (25 ℃) , 100, 200, 250, 300 and 350 ℃ .Through the characterization of different temperature wear materials and dual surface morphology, the friction behavior and wear mechanism under high temperature conditions were studied.The results show that with the wear of With the increase of ambient temperature, the wear rate of thermoset polyimide increases first and then decreases and then increases, while the friction coefficient decreases all the time, which is attributed to the change of mechanical properties of the polymer contact surface. The wear mechanism under different temperature conditions is also different. The wear under 25 and 100 ℃ conditions is mainly fatigue wear and abrasive wear. As the ambient temperature increases to 200 ℃, some of the worn surface segments tend to shear and form a layer Uniform transfer film and reduce the abrasive wear; when the temperature rises to 250,300 and 350 ℃, the wear of the surface of the molecular chain movement more Intense, continuous extrusion under test load, a force to break the molecular chains peeling, a sharp increase in the wear rate, the performance of adhesive wear, and the higher the temperature, the greater the wear rate.