Polymers from Renewable Resources. XXVIII. Synthesis, Characterization, and Thermal Studies of Semi-Interpenetrating Polymer Networks Derived from Castor-Oil-Based Polyurethanes and Cardanol Derivatives

Abstract

Cashew nut shell liquid (CNSL) and its polymeric products find a wide range of industrial applications due to their higher thermal stability and mechanical strength. Cardanol is obtained from the vacuum distillation of CNSL at 230–240°C. The distilled cardanol was reacted with acetic anhydride and orthophosphoric acid to get acetylated cardanol (AC) and phosphorylated cardanol (PC), respectively. The Fourier transform infrared spectra of the above cardanol derivatives have been reported. A number of castor-oil-based polyurethanes were obtained using diisocyanates like hexamethylene diisocyanate and diphenylmethane diisocyanate. Then, a number of semi-interpenetrating polymer networks (semi-IPNs) were synthesized using the polyurethane, cardanol derivatives (AC and PC). The semi-IPNs were subjected to thermal analysis and the kinetic parameters were calculated by the Freeman and Anderson method.