Optimization of Tensile Properties of Melt‐Processed Polylactic Acid/ Cissus quadrangularis Fiber Composites

ABSTRACT The limited load‐bearing capability of polylactic acid (PLA) restricts its use in biomedical applications such as orthopedic scaffolds, where mechanical robustness is essential. Reinforcing PLA with biofunctional natural fibers offers a sustainable route to overcome these limitations. In this study, Cissus quadrangularis (CQ), a fiber with high cellulose content and osteogenic potential, was employed as reinforcement for PLA to develop biodegradable composites. The composites were fabricated through melt extrusion followed by injection molding, and the effect of fiber content, extrusion temperature, and molding pressure on ultimate tensile strength (UTS) was systematically evaluated using a Taguchi L9 orthogonal design. Regression modeling revealed molding pressure as the most influential factor, and a Genetic Algorithm (GA) was integrated with the regression model to achieve global optimization of processing conditions. The optimized combination of 14.98 wt.% fiber, 160.9°C extrusion temperature, and 29.76 MPa molding pressure yielded a UTS of 43.05 MPa, closely matching experimental validation with < 1% error. Fractographic analysis confirmed effective fiber–matrix interaction under optimized conditions. This integrated Taguchi–GA framework highlights the significance of combining statistical design with metaheuristic optimization to enhance the performance of natural fiber composites and provides a pathway for designing mechanically robust PLA‐based biomaterials.