Comparison of Cashew Nut Shell Liquid (CNS ) Resin with Polyester Resin in Composite Development

Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin) so obtained was mixed with cobalt amine (accelerator), methyl ethyl ketone peroxide (catalyst) to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic) resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL) resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa) to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements) and fillers are used in the fibre-reinforced plastic composite developments.KEYWORDS: CNSL resins, polyester resins, composite development, strength test