Effect of carbonized watermelon rind powder on the mechanical and thermal properties of unsaturated polyester composites: A special insight to chemical resistance and value addition

This study focuses on the preparation and characterization of bio-based filler derived from natural fruit waste and its utilization in unsaturated polyester composites. Particle size analysis, energy dispersive x-ray spectroscopy, and Fourier transform spectroscopy were used to characterize the size and composition of the filler namely carbonized watermelon rind filler, called carbonized watermelon rind filler. The filled composites (0%, 5%, 10%, and 15%) were prepared and their mechanical properties such as tensile, flexural, and impact were tested. It was found that tensile modulus had increased to 17% at 10% filler loading as compared to unfilled. These results were supported by scanning electron microscopy measurements of the fractured surface of the composites. All the fabricated composites resisted well against the chemicals and it indicates that the composites have excellent chemical resistance. The thermal properties were characterized by Thermogravimetric analysis which revealed that there was no improvement in thermal degradation temperature of the filled composites suggesting a way of thermally recycling the composites.