改性凹凸棒石及硅灰石填充PTFE的摩擦性能研究

Tribological Properties of PTFE Filled with Modified Palygorskite and Wollastonite

采用硅烷偶联剂(KH550)及十六烷基三甲基溴化铵(CTAB)对凹凸棒石粉体进行改性,并将改性前后的凹凸棒石粉体与硅灰石复合填充至聚四氟乙烯(PTFE),制备PTFE复合材料。采用傅里叶红外光谱仪(FTIR)、扫描电子显微镜(SEM)、邵氏硬度计、环块摩擦磨损试验机、万能试验机对改性凹凸棒石粉体的理化性能及复合材料摩擦学性能进行表征。结果表明:凹凸棒石及硅灰石的加入可以降低复合材料的磨损率。经CTAB改性的凹凸棒石与硅灰石填充至PTFE,复合材料的邵氏硬度增至70,磨损率降至1.54×10^(-6)mm^(3)/(N·m),压缩性能提高40%左右。对凹凸棒石进行表面改性,可提高粉体与PTFE基体的界面结合,从而改善复合材料摩擦学性能和力学性能。

Attapulgite powder was modified by silane coupling agent(KH550)and cetyltrimethylammonium bromide(CTAB),and the modified attapulgite powder and wollastonite were filled into polytetrafluoroethylene(PTFE)to prepare PTFE composites.The physical and chemical properties of the modified attapulgite powder and the tribological properties of composites were characterized by Fourier transform infrared spectrometer(FTIR),scanning electron microscope(SEM),shore hardness tester,ring block friction and wear tester and universal testing machine.The results show that the addition of attapulgite and wollastonite can reduce the wear rate of the composites.The Shore hardness of the composites is increased to 70,the wear rate is decreased to 1.54×10^(-6)mm^(3)/(N·m),and the compression performance is increased by about 40%,when CTAB modified attapulgite and wollastonite are filled into PTFE.Surface modification of attapulgite can improve the interfacial bonding between powder and PTFE matrix,thus improving the tribological and mechanical properties of composites.