Study On Enhanced Effect Of Polyether-ether- Ketone-based Carbon Fiber Composites

PEEK is a kind of semi-crystalline and high performance engineering plastic, it possesses high glass transition temperature (Tg= 143 ℃), high melting point (Tm= 340 ℃) and high continuous service temperature (260 ℃). It has received much attention owing to its high elastic modulus, exceptional thermal stability, good chemical resistance, radiation resistance and excellent wear resistance. Because of PEEK has these outstanding properties, therefore, it has been applied in many sophisticated industries, such as aerospace, automotive industry, electronic, and medical instruments. The most prominent feature of carbon fiber (CF) is a high strength, high modulus and low density. In addition, it also possesses the properties of high temperature resistant, acid resistant, low thermal expansion coefficient, high thermal conductivity, low friction coefficient, good lubricity and electrical conductivity. In the composites materials, carbon fibers have been successfully used as reinforcement in PEEK matrix composites. CF reinforced PEEK composites further enhance the mechanical properties, thermal stability and tribological properties of PEEK. It expanded the applications in the areas of aerospace, automotive industry, electronic, and medical instruments.Three parts are mainly in this paper, in the first part, CF as a reinforced material to preparation of the CF/PEEK composite, and the CF are treated by nitric acid. Furthermore, studied the different processing time on the interface bonding performance and mechanical properties of composites under 110 ℃; in the second part, SiO2/PEEK composites are prepared by adding different content of SiO2 nanoparticles, also studied the content of nano-SiO2 on the morphology, crystallization behavior and thermal performance of the composites; CF/SiO2/PEEK composites have been prepared successfully, and studied the influence of different content of nano-SiO2 on the friction and wear properties of the composites.The results of the first part showed that heating CF in nitric acid at 110 ℃ for 1.5 h, CF/PEEK composites exhibited the most outstanding interface bonding properties and mechanical properties. Moreover, the tensile strength and bending strength increased by 17.28% and 17.88%, respectively. Thus, comprehensively consideration of the interface bonding properties, mechanical properties and experiment efficiency, nitric acid process 1.5 h under 110 ℃ are the best processing condition. In the second part, XRD and DSC showed that there are no obvious interactions between nano-SiO2 and PEEK, and just a simple physical blending. At 5wt% nano-Si02 loading, SiO2 are dispersed in the PEEK matrix uniformly. But further increased the content of SiO2,there are some aggregation of SiO2 in the PEEK matrix. By addition of SiO2, the crystallization temperature and the crystallinity of the composites reduced slightly, but improved the stiffness and thermal stability of the composites. In the third part, the friction coefficient and wear rate of the CF/SiO2/PEEK composites decreased by addition of SiO2, and showed the lowest of wear rate at the 5wt% SiO2 additive.