Wood-plastic Composite Based on Recycled Polypropylene and Amazonian Tucuma (Astrocaryum aculeatum) Endocarp Waste

Natural fibre-based composites have been investigated as a viable ecological alternative to conventional materials, combining low-cost and sustainable features to engineering products. In tropical countries, such as Brazil, there are many lignocellulosic residues that are discarded in nature, polluting the environment, such as the Tucuma fruit, which generates about 50 tonnes/month of solid waste only in the city of Manaus (State of Amazonas). This work investigates a novel wood-plastic composite (WPC) made from recycled polypropylene (PP) and Tucuma endocarp powder (TEP) without coupling agents that encompasses social and environmental issues. WPCs are composed of 10, 20, 30, 40 and 50 wt% of TEP combined with PP by injection moulding, being characterised by SEM, FTIR, flammability, water absorption, ageing, tensile, compressive, three-point bending, impact and scratch tests. TEP does not react to the matrix phase, presenting 49.4 % and 37.4 % of cellulose and lignin, respectively. In general, the incorporation of TEP not only increases the elastic modulus and the dynamic friction coefficient, but also reduces the strength and the burning rate of WPCs. WPC preserves its physical integrity after ageing, absorbing up to 1.6 % of water. Composites made with 20 wt% of TEP can be considered promising materials to be used as wood plastic for sustainable engineering applications.

Automated summary

The study investigated a novel wood-plastic composite made from recycled polypropylene and Tucuma endocarp powder without coupling agents, which addresses social and environmental issues. The addition of Tucuma endocarp powder can increase the elastic modulus and dynamic friction coefficient, while reducing the strength and burning rate, showing potential for sustainable engineering applications.