Properties of Surface-Modified Carbon Fiber Reinforced Polytetrafluoroethylene Composites

The carbon fiber （CF） was treated by silanizing and silanizing + fluorinating with silane coupling agent and fluorinating agent. The microstructure and elemental analysis on surface of CF were carried out. The thermal properties, mechanical properties and tribological properties of PTFE composites reinforced with CF treated by silanization treatment and silanization and fluorination treatment were studied. The results show that silanization treatment introduced organic siloxyl groups, fluorination treatment introduced fluorine-containing functional groups, the introduction of these functional groups could improve the interfacial bonding performance. Compared with those of glue removal CF reinforced PTFE composites, the glass transition temperature of PTFE composites reinforced with CF treatment by silanization treatment and silanization and fluorination treatment increased, and the thermal expansion coefficient decreased; the compressive yield strength, tensile strength and percentage elongation after fracture increased; the friction coefficient improved, and the volume wear rate decreased. The modification effect of silanization and fluorination treatment was the best. Compared with those of glue removal CF reinforced PTFE composites, the compressive yield strength, tensile strength and percentage elongation after fracture increased by 26.1%, 22.6% and 28.5%, respectively.