Fruit waste-derived hybrid biofillers as a potential reinforcement in 3D printed biocomposites for building construction applications

Exhausting natural resources, the low biodegradability of plastic wastes, concerns about agricultural waste, and the high demand for composites in diverse fields have driven the world towards the valorisation of fruit-derived wastes in the development of biocomposites. In the present work, a hybrid fruit waste-derived biofillers from orange and banana peel were reinforced with a biopolymer such as poly-lactic acid (PLA) in the fabrication of biocomposites by implementing a 3D printing technique. The effect of loading fractions of biofillers such as 5, 10, 15 and 20 wt% (in equal proportion) on the mechanical performances of the biocomposites was investigated. The mechanical performances of the biocomposites improve with the incorporation of biofillers. However, invariability in the behaviours of the biocomposites with reinforcements was observed. The incorporation of 5 wt% of biofillers with 95 wt% of polylactic acid has resulted in an optimal compressive strength of 70.25 MPa, whereas the reinforcement of 20 wt% of biofillers with 80 wt% of polylactic acid has obtained a maximum hardness and flexural strength of 70 (shore D) and 44.2 MPa, respectively. The optimum impact strength and bending modulus were found to be 21,000 kj/m² and 2310 MPa, respectively, for the composite having 15 wt% of biofillers and 85 wt% of polylactic acid. Scanning Electron Microscopy (SEM) of the filaments has explored the compatibility between the biofiller and matrix. The fractography analyses have observed a change in the failure modes and mechanisms with the test conditions and compositions. The study has demonstrated the viability of biofillers in composites and offers a sustainable solution to agricultural wastes.