Direct Extrusion–Injection Molding of Sustainable Biocomposites Using Lignocellulosic Fibers/PBAT/PLA

In the current experimental investigation, biocomposites (BCs) were fabricated using banana fibers (BF) and pineapple fibers (PF) and poly(butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA) matrices using melt compounding and injection molding. Banana fiber-based biocomposites (BF-BCs) and pineapple fiber-based biocomposites (PF-BCs) were fabricated by incorporating (10-30 wt.%) natural fibers (BF and PF) and (10-30 wt.%) PLA into the PBAT matrix. The developed BCs were characterized with respect to their hygroscopicity, thermal behavior, chemical constituents, crystallinity, mechanical performance, and morphological features. Simultaneously, fibers were also characterized in terms of surface morphology, thermal and chemical constituents, and crystallinity. BF showed marginally higher moisture removal during the thermal analysis as compared to PF. At 30 wt.% of fiber loading, PF-BCs showed marginally higher tensile strength, nearly 1.4 times and moderately higher flexural strength (1.2 times) as compared to the BF-BCs. These results indicate that PF reinforcement provides better mechanical performance and lower water uptake relative to BF in BCs. Overall, this investigation demonstrates that natural fiber reinforcement offers an effective strategy to balance the ductility (~ 670%) of PBAT and the brittleness (~ 5%) of PLA, enabling the design of biocomposites for sustainable industrial products.