Increasing environmental awareness and the scarcity of nonrenewable resources have accelerated the development of biodegradable composites derived from natural materials. This work explores the influence of potato starch as a microscale biomodifier and jute and banana fibers as macroscale reinforcements on the mechanical, thermal, and morphological performance of poly(butylene adipate-co-terephthalate) (PBAT)/polylactic acid (PLA) biocomposites. Six distinct composite systems─raw and starch-coated jute, banana, and their hybrid combinations─were fabricated by using compression molding to evaluate the combined effects of starch coating and fiber hybridization. The experimental results reveal that starch modification significantly enhanced fiber–matrix adhesion, leading to increased density, crystallinity, and interfacial compatibility as confirmed by Fourier transform infrared and differential scanning calorimetry analyses. Starch-treated banana composites exhibited the highest compressive strength (5.12 MPa) and modulus (691 MPa), while hybrid jute–banana systems showed an improved balance between stiffness and ductility. Tensile and flexural results followed similar trends: the starch-coated banana composites attained the greatest tensile strength (41.33 MPa) and bending strength (26.71 N/mm2), while the hybrid composites presented superior flexural modulus (1492 N/mm2) and impact energy absorption (41.08 kJ/m2). The overall improvement in strength, modulus, and toughness highlights the synergistic effect of starch treatment and fiber hybridization on interfacial bonding and load transfer efficiency. These biocomposites exhibit the potential for sustainable applications such as biodegradable packaging, automotive interior components, and structural panels where environmental compatibility and mechanical reliability are essential.
Syduzzaman et al. (Wed,) studied this question.