Effect Of Graphene On The Carbon Fiber Reinforced Poly(ether Ether Ketone) Composites

Poly(ether ether ketone)(PEEK) is a special type of engineering thermoplastics with excelled comprehensive performances such as high mechanical properties, wear resistance, fatigue resistance, drug resistance, heat resistance, radiation resistance, flame retardancy, flexibility and processing formability. Carbon fiber(CF) possesses a lot of excellent performance, such as high mechanical properties, high specific modulus and specific strength, high temperature resistant, friction resistance, corrosion resistance, fatigue resistance, low density, low thermal expansion coefficient, easy textile processability, high electromagnetic shielding, high thermal conductivity and electrical conductivity. Therefore, CF is widely used in polymer matrix composites as a reinforced material. The resistance to friction and wear properties, mechanical properties and thermal properties of CF/PEEK composites were notably higher than PEEK.Graphene(GE) has been recognized as the thinnest, strongest and most electrical conductive material so far in the world, and with high thermal conductivity, good lubricity, large specific surface area, as well as good flame retardancy. We added different contents of graphene into the composites to expand the application of the CF/PEEK composites in aerospace, electronics, petrochemical industry. The effect of the graphene on the morphology, thermal conductivity, friction performance, phase transition temperature, thermal stability and mechanical properties of the composites was investigated.Graphene was successfully prepared by chemical oxidation reduction method. PEEK/GE/CF composites with different weight percentages of graphene were manufactured through ball milling and compression molding. Scanning electron microscopy showed that the graphene was uniformly distributed in the matrix regions. Thermal conductivity measurements demonstrated that addition of 0.7 wt% graphene sharply improved the thermal conductivity of the composites. The thermal conductivity of the PEEK/0.7 wt% GE/CF composites is 35.5% higher than that of the composites without graphene. Tribological tests revealed that the friction coefficient and wear rate rapidly decreased with the addition of graphene. In the studied range, the friction reduction and wear resistance performance of PEEK/CF composites filled with 0.7 wt% GE is the most effective. The friction coefficient and wear rate of the composites was 0.37 and 6.4×10-6 mm3/N m, respectively. The wear resistance of the composites was improved by 70.9% compared with those of PEEK/CF composites. Meanwhile, the obtained PEEK/GE/CF laminates also possessed excellent mechanical and thermal properties. Thus, graphene-reinforced PEEK/CF composites possessed better overall properties than conventional PEEK/CF composites.