The present study focused on the thermal and mechanical performance of natural fiber (banana and kenaf) reinforced polylactic acid composites added with coconut and walnut shell powder as a filler. Seven different composite specimens were formulated based on weight percentages of fibers, fillers, and PLA-based matrix. The outcomes showed that incorporated fibers and fillers enhanced the mechanical and thermal behaviour of prepared samples compared to neat PLA samples. Lower void percentage (less than 10%) for all prepared composite samples secure the appropriateness of designed compression moulding techniques for sample production. Thermal conductivity of neat PLA sample 0.18 wm−1k−1 was lowest while maximum thermal conductivity value of 0.41 wm−1k−1 was achieved by hybrid Banana/Kenaf/PLA/Walnut filler composite. Maximum value of hardness was displayed by hybrid Banana/Kenaf/PLA/Walnut filler composite as 99 Shore-D. Banana/Kenaf/PLA/Walnut filler composite indicates utmost tensile strength, and young’s modulus of 59.08 MPa and 3.9 GPa while minutest tensile strength and young’s modulus of 24.47 MPa and 2.1 GPa was got by neat PLA sample. The mechanical properties of test specimens enriched across numerous mechanical tests due to the hybridization of different fiber mats with miscellaneous fillers.
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