Sustainable and lightweight biopolyamide hybrid composites for greener auto parts

Sustainable bio-based materials have remarkable environmental and health impacts throughout their life cycles. Over the past few decades, green biocomposites have attained rising attraction in the automotive industry, as they can be customized to meet many of its prime requirements. Polyamides are the most common engineering polymers used in the automotive industry due to their desirable properties. This study focuses on improving thermo-mechanical properties of wood fibre/carbon fibre biopolyamide hybrid composites for automotive applications. Important material properties such as tensile, flexural, and impact strengths along with density, melt flow index, and heat deflection temperature were studied and correlated with their SEM surface morphologies. The composites were produced by melt-compounding of the fibres and polymers via extrusion and injection moulding. All hybrid composites exhibited greater thermo-mechanical properties compared to wood fibre composites. Use of a polymer blend of polyamide and polypropylene matrix in the composites further enhanced performance properties of the composites while reducing the costs. The developed hybrid composites had lower densities compared to the existing materials used in some auto parts. The mechanical properties of polymer blend composites, including tensile, flexural, and impact properties were higher than those of polyamide composites. Image analysis showed efficient fibre-matrix adhesion with good fibre dispersion in the composites. A significant improvement in heat deflection temperature was observed for the hybrid polymer blend composites. The study indicated that the developed hybrid bio-based composites are promising candidates with light-weighting potential for automotive structural applications, where high stiffness and thermal resistance are required.