Abstract: Polypropylene (PP)-based composites reinforced by three different carbon fiber (CF) were prepared by melt extrusion and their mechanical properties, melt fluidity, hardness and thermal stability were investigated. The results indicated that the composites achieved much higher tensile strength, flexural strength and impact toughness when using the CF with a length of 7 mm compared with the other two types of CF. However, the incorporation of these three types of CF reduced the melt fluidity of the composites. The higher the content of CF, the lower the melt fluidity. However, higher CF content resulted in greater hardness. The thermal stability was also improved with the addition of CF. Moreover, the presence of CF did not affect the melting temperature of the composite but improved their crystallization temperatures.

Key words: polypropylene, carbon fiber, composite, specification, fiber content