Processing-dependent reinforcing behavior of garlic peel and pineapple leaf fibers in poly(butylene succinate) all-biocomposites

Poly(butylene succinate) (PBS) composites reinforced with garlic peel fiber (GF) and pineapple leaf fiber (PALF) were prepared using a two-roll mill followed by compression molding at 120 °C and 150 °C with fiber loadings of 10 and 20 wt%. Fiber morphology after processing, flexural, impact and thermal behavior were investigated. PALF retained a higher effective aspect ratio after processing than GF; however, this morphological advantage did not translate proportionally into the flexural enhancement expected from morphology alone under the processing conditions employed. Flexural properties showed clear dependence on testing direction and molding temperature, with higher values observed in the longitudinal direction and for specimens molded at 120 °C, while increasing fiber loading enhanced flexural strength and modulus for both fiber systems. Impact behavior exhibited trends distinct from quasi-static flexural response. Overall, the results demonstrate that reinforcing efficiency in PBS-fiber composites is strongly processing-dependent and governed by how fiber morphology and orientation are translated into mechanical performance.