Development of Biomass-Reinforced PLA Composites for 3D Printing

In this study, poly(lactic acid) (PLA) composites reinforced with lignocellulosic materials were developed to reduce the environmental impact of plastics. PLA–biomass composites, incorporating cork, rice husk, coffee grounds, or oak gall at loadings of 2.5% to 20.0% (w.w−1), were produced via melt extrusion and subsequently used in 3D printing. The results showed that the incorporation of biomass reduced the mechanical performance of the composites despite being adequate for 3D printing. Rice husk and coffee grounds increased filament density, whereas cork and oak gall decreased it. Thermal properties were largely preserved, with glass transition temperatures (Tg) near 70 °C and decomposition temperatures well above the printing temperature, indicating that thermal resistance was not compromised. SEM analysis of the printed objects revealed good layer definition for neat PLA and rice husk composites, highlighting rice husk as the most promising biomass filler in terms of print quality. Hence, the results demonstrated that incorporating rice husk into PLA offers a viable route for more sustainable composites suitable for additive manufacturing.