SUMMARY
In recent studies importance has been given to the use of natural products from renewable resources due to the decrease in the supply and price escalations of petroleum raw materials. Cardanol based resole type phenolic resin has been synthesized by condensing cardanol with furfural in a particular mole ratio using dicarboxylic acid catalyst such as phthalic acid. Polyurethane sheets were prepared by treating cardanol furfural resin with 4,41 – methylene bis(cyclohexyl isocyanate) and the catalyst dibutyltin dilaurate. Natural fibres are prospective reinforcing materials and their use until now has been more traditional than technical. Among the various fibres sisal is of particular interest in that its composites have high impact strength besides having moderate tensile and flexural properties compared to other fibres. Fibre reinforced polyurethane composites have been prepared by treating sisal fibre (10%) into polyurethane. The physico chemical, spectral and thermal properties of polyurethane and fibre reinforced polyurethane composites have been studied.