Thermally stable and high impact toughness chopped PI fiber-reinforced PEEK composites

Chopped polyimide (PI) fiber-reinforced polyether ether ketone (PEEK) composites with different fiber content (0%, 10%, 20%, and 30%) were prepared via melt extrusion using a twin-screw extruder. The impact strength of these composites significantly improved from 4.9 kJ m-2 to 9.3 kJ m-2 with the increase of the PI fiber content from 0% to 30%. Tensile strength, tensile modulus, and flexural strength also increased with the increase in PI fiber content. In addition, the heat deflection temperature increased significantly from 160 degrees C to 318 degrees C. The results of the dynamic mechanical analysis revealed that the storage modulus increased considerably. The relationship between mold temperature and composite properties was investigated, and using differential scanning calorimetry, it was shown that the increase in mold temperature improved the degree of polymer crystallization and the bonding capability of the fiber and resin interface. As a result, the mechanical properties of the composite material were improved.