Effect of Filler-Filler Interactions on Mechanical Properties of Phenol Formaldehyde Based Hybrid Composites

Abstract

Mechanical properties of phenol formaldehyde (PF) based hybrid composites reinforced with molybdenum disulphide (molykote; MC), copper (Cu), graphite (Gr) and antimony (Aty) particles in micron size, having different shape and aspect ratio, are studied. Incorporation of MC, Cu and Gr enhanced the hardness, compression and flexural properties of PF based hybrid composites. A slight decrease in density was observed in MC + Gr (A5) reinforced PF based hybrid composites, making these composites suitable in weight susceptible applications. The investigations showed that the control sample A1 without MC/Cu/Gr/antimony (control sample) exhibited poorer mechanical properties. Addition of Cu, MC and Gr to the control sample resulted in moderate improvement in the mechanical properties. However, hybridization of the control sample with Gr + Aty (A6) showed lower mechanical properties compared to that of composites filled with MC and Gr (A4 and A2) respectively. This decrease was ascribed to the tendency of non-uniform dispersion, deprived bonding of Aty particles as well as poor filler-matrix adhesion. When Aty was replaced with Gr + MC (Sample A5), filler-filler with matrix interaction appears to be increased, resulting in increased strength and modulus. The developed PF based hybrid composites have exhibited improved mechanical properties and these composites with detailed thermal and tribo-studies may be recommended for railway braking applications.