Optimization of mechanical/thermal properties of glass/flax/waste cotton hybrid composite

In quest of finding solutions of high cost and non-biodegradability issues of synthetic fibre-based composites, hybridization of natural fibres is a focused approach recently. The current study is focused to find out the optimized proportion of natural recycled fibre with virgin synthetic fibre which offers maximum mechanical properties with low cost. Synthetic/recycled (glass/waste cotton) and synthetic/natural/recycled (glass/flax/waste cotton) hybrid composites were developed and their mechanical and thermal properties were characterized. First, the mechanical properties, i.e. tensile strength, flexural strength and impact strength, that are most important for structural applications were studied. Second, the coefficient of thermal expansion of developed composites was determined. For optimization of the aforesaid properties of the hybrid composites, a statistical tool, i.e. grey relational analysis, was applied. The grey grades show that with the inclusion of waste cotton fibre, there is no significant decrease in mechanical properties, whereas there is a drastic decrease in cost. Furthermore, utilization of waste fibres in the composites is the best solution, as the poor mechanical properties of waste fibre are not as much pronounced in the composite form, thanks to continuous and strong interface of resin with recycled fibres.