Optimization and modelling of the fracture inhibition potential of heat treated doum palm nut fibres in phenolic resin matrix polymer composite: a Taguchi approach

The chemical treatment of natural fibres for its surface modification for the development of polymer composites is popular but it comes with an adverse effect of a chemical change of the fibres. In this study, the surface modification of natural fibres (doum palm nut (DPN) fibres) with low-temperature heat treatment (30 °C–75 °C) has been reported as an alternative method to the treatment of natural fibres for the development of polymer composites. Taguchi method of the design of experiment was employed to determine the effect of temperature and fibre content on the mechanical properties (hardness and fracture toughness) of DPN fibre-reinforced phenolic resin polymer composite. The process showed that the best combination of fibre content and fibre treatment temperature for optimum hardness and fracture toughness and results proved to be at 5% and 75 °C respectively. Statistical analysis established the significance of heat treatment in improving the fracture toughness of DPN fibre reinforced phenolic resin composites. Physical observation with scanning electron microscope and Fourier-transform infrared spectroscopy confirmed the improvement in interfacial bonding between the fibre and the matrix with the increase in fibre treatment temperature without a change in the chemical properties of the treated fibres. The study concludes that the treatment of fibres with temperature is an alternative and effective method to the chemical treatment.