Short carbon fiber reinforced polycarbonate composites: Effects of different sizing materials

In this paper, effects of the sizing material type and level on the mechanical, electrical and morphological properties of the short carbon fiber (CF) reinforced polycarbonate (PC) composites were investigated. Unsized CF and the CFs which were sized with epoxy/phenoxy(EPO_PHE), polyimide(PI) and phenoxy(PHE) were used as reinforcement materials. Fiber length distribution analysis indicated that sizing protected the CFs breakage into the smaller lengths during the processing. Effects of the sizing material type and level on the mechanical properties of CF reinforced PC composites were investigated by means of tensile and izod impact strength tests. Tensile test results revealed that tensile strength and modulus values of sized CF reinforced PC composites were higher than that of unsized CF reinforced PC composites. Besides, effect of the sizing material level on the tensile properties of composites changed with respect to the sizing material type. It was also found that the measured effects of the sizing agent type and level on the notched izod impact strength of composites were not so significant. In addition to this, it was found that sized CF reinforced PC composites had higher electrical conductivity values than unsized CF reinforced PC composites. Also, PHE sized CF reinforced composites had the highest electrical conductivity value among the other composites. Better interactions between EPO_PHE and PHE sized CF and PC matrix were observed from the scanning electron microscope analysis. As a result of this study, PHE and EPO_PHE sized CFs can be suggested as proper reinforcements for PC matrix.