微米和纳米SiO2改性聚四氟乙烯的摩擦磨损性能

使用超细及纳米SiO₂颗粒填充改性聚四氟乙烯塑料。测量其摩擦系数、磨损系数、结晶度,得到了填加量与复合材料摩擦系数、磨损系数和结晶度的关系曲线,并使用扫描电镜(SEM)对其表面形貌进行了分析。结果表明,无论微米或纳米SiO₂、表面处理后的纳米SiO₂,均使PTFE的摩擦系数有所提高,而耐磨损性能也有大幅度的提高。填充量小于6%时,填加未经偶联剂处理的纳米SiO₂的SiO₂/PTFE复合材料的磨损率降低98.5%;填充量大于6%以后,磨损率趋于稳定;填充量为6%时,摩擦系数仅从未加填料时的0.1提高为0.12。而偶联剂表面处理的纳米SiO₂复合材料的摩擦系数提高幅度最小。

FRICTION AND WARE PROPERTIES OF PTFE-BASED COMPOSITES FILLED WITH MICRON AND NANOMETER SiO2 PARTICLES

The effects of polytetrafluoroethylene (PTFE)-based composites filled with nanosized SiO_2 and micronsized SiO_2 on friction and wear properties were investigated. The friction coefficient, wear rate and crystallinity were measured. The friction surface was observed by scanning electron microscopy (SEM). The results show that the addition of the silica micron-particles or nano-particles and surface treatment not only increases the friction coefficient of PTFE-based composites, but also results in largely decreasing the wear rate of SiO_2/PTFE composites. When the filler mass fraction is lower than 6%, the wear rate of the SiO_2/PTFE composites filled with untreated nanosized SiO_2 falls 98.5%, while the wear rate trends to be stable after the filler mass fraction is higher than 6%. However, adding 6% of nanosized SiO_2, the friction coefficient of SiO_2/PTFE composites is only elevated from 0.1 of the pure PTFE to 0.12. The friction coefficient of SiO_2/PTFE composites filled with nanosized SiO_2 treated by coupling agent is improved to the smallest elevation.