Preparation And Characterization Of Short Carbon Fiber Reinforced Polyetheretherketone Composites

In this paper, the hot-pressing process for the preparation of short carbon fiber reinforced polyetheretherketone (SCF/PEEK) composites which are to be used as external fixation was studied. The effects of the length and volume fraction of the fiber on the mechanical properties of the SCF/PEEK composites were investigated. Additionally, the effect of air-oxidation on the mechanical properties was discussed, and the mechanical properties of fiber reinforced composites after moisture absorption were studied. Furthermore, the fatigue resistance, the friction and wear characteristics and the X-ray penetrability of the composites were also assessed. The experimental investigation was carried out to evaluate the feasibility of the composites used as in external fixation.It was shown that short carbon fibers were uniformly dispersed in PEEK by using the ethanol and glycol (with the bulk factor of 5:1) as dispersants. The composites had lower mechanical properties under a high cooling velocity when prepared by hot-pressing process. It showed better key properties when the PEEK 450 was chosen as the matrix material than the PEEK 450. It was found that the SCF/PEEK composites with the fiber volume fraction of 20% and the fiber length of 3~6 mm showed the highest flexural and shear strengths. It was also shown that the mechanical properties of SCF/PEEK composites were better than neat PEEK and SCF/Epoxy composites with identical fiber volume fraction. The flexural strength, modulus and shear strength of SCF/PEEK and SCF/Epoxy composites increased after the fiber surface oxidation at 500℃for one hour, while the impact strength hardly changed. Compared with SCF/Epoxy composites, SCF/PEEK composites had better friction and wear characteristics. The friction coefficient of SCF/PEEK composites increased initially, then decreased, and at last leveled off. When the fiber length was 3~6 mm, the SCF/PEEK composites showed better friction and wear characteristics than 1~3 mm. After fiber surface oxidation at 500℃for an hour, the friction and wear characteristics of the composites were increased. The flexural strength and modulus of the SCF/PEEK composites declined appreciably after sterilization treatment at 121℃for an hour, while the impact strength increased slightly. The flexural strength and modulus of the SCF/PEEK composites decreased slightly after 100,000 times of cyclic flexure. SCF/PEEK composites possessed excellent X-rays penetrability.In conclusion, the properties of SCF/PEEK composites can meet the needs of external fixation in terms of their properties. They are materials for bone fixation with great market potentials.