不同混合工艺对PTFE复合材料性能的影响  

Effects of Different Mixing Processes on Properties of PTFE Composites

作　　者：樊学峰 许永坤 李萌 Fan Xuefeng;Xu Yongkun;Li Meng(Zhejiang Changsheng Slide Bearing Co.,Ltd,Jiaxing 314100,China)

机构地区：[1]浙江长盛滑动轴承股份有限公司,浙江嘉兴314100

出　　处：《工程塑料应用》2022年第4期65-69,75,共6页Engineering Plastics Application

摘　　要：研究了不同混合设备及混合工艺对聚四氟乙烯(PTFE)复合材料力学性能、摩擦磨损性能的影响。对工业上常用的混料设备混合特点及对PTFE混料的适用性进行分析评价。然后选用生产上常用的碳纤维、氧化铝作为PTFE的填料,其中氧化铝经过硅烷偶联剂处理,采用冷压烧结法制备出PTFE复合材料,研究混料过程中的不同温度、转速等工艺参数对材料分散性及性能的影响。利用光学显微镜、万能材料试验机、冲击试验机、环-块摩擦试验机表征材料的截面形貌、力学性能和摩擦磨损性能。结果表明,混料过程中的最高温度是影响PTFE混合的关键因素,控制混料过程中的最高温度低于19℃,提高高速混合机转速可提高材料的分散均匀性,但转速过高会引起PTFE发热而引发团聚。将PTFE原料进行预先冷却,然后在混合过程中采用液氮冷却,当混合机转速达到2?500 r/min时,混合分散效果和PTFE复合材料的综合性能最佳,拉伸强度、断裂伸长率和冲击强度分别达到17.5 MPa,100%和65.2 kJ/m^(2),磨损率和摩擦系数分别为6.38×10^(-6)mm^(3)/(N·m)和0.21。The effects of different mixing equipment and mixing process on the mechanical properties,tribological properties of polytetrafluoroethylene(PTFE)composites were studied.The mixing characteristics of mixing equipment commonly used in industry and its applicability to PTFE mixing were analyzed and evaluated.Then carbon fiber and alumina commonly used in production were selected as PTFE fillers.The fillers were treated with silane coupling agent,and then PTFE composites were prepared by cold pressing sintering method.The effects of different process parameters such as temperature and rotating speed on the dispersion and properties of composites were studied.The cross-sectional morphology,mechanical properties and tribological properties of the composites were characterized by optical microscope,universal material testing machine,impact testing machine and ring-block friction testing machine.The results show that the maximum temperature in the mixing process is the key factor affecting the mixing of PTFE.Controlling the maximum temperature in the mixing process to be lower than 19℃and increasing the speed of the high speed mixer can improve the dispersion uniformity of composites,but too high speed will cause PTFE heating and agglomeration.When the PTFE raw material is pre-cooled and cooled by liquid nitrogen in the mixing process,and the speed of the high speed mixer reaches 2?500 r/min,the mixing dispersion effect and comprehensive performance of composite are the best.The tensile strength,elongation at break and impact strength reach 17.5 MPa,100%and 65.2 kJ/m^(2)respectively,and the wear rate and friction coefficient are 6.38×10^(-6)mm^(3)/(N·m)and 0.21 respectively.

关 键 词：聚四氟乙烯 共混改性 混合工艺 复合材料 

分 类 号：TQ327[化学工程—合成树脂塑料工业]