Studies on the blends of cardanol-based epoxidized novolac type phenolic resin and carboxyl-terminated polybutadiene (CTPB), I

Six blend samples were prepared by physical mixing of epoxidized cardanol-based novolac type phenolic resin with different weight ratios of carboxyl-terminated polybutadiene (CTPB) liquid rubber ranging between 0 and 25 wt% with an interval of 5 wt%. Blend sample containing 15 wt% CTPB showed least cure time at 150 °C amongst all other blend samples. The formation of various products during the curing of blend samples has been studied by Fourier-transform infra-red (FTIR) spectroscopic analysis. The tensile strength and elongation-at-break of the cured samples increased up to 15 wt% in the blend and decreased thereafter. This blend sample was also found to be the most thermally stable system. The blend morphology, studied by scanning electron microscopy (SEM) analysis, was finally correlated with the structural and property changes in the blends.