Acoustic and Functional Properties of PLA‐Walnut Biocomposites

ABSTRACT The aim of this study is to develop and characterize biodegradable biocomposites based on polylactic acid (PLA) reinforced with walnut shell particles. Composite specimens were fabricated via compression molding with walnut shell loadings ranging from 10% to 50%. A comprehensive suite of analyses was conducted, including scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile and impact mechanical tests, and acoustic emission (AE) monitoring to elucidate fracture mechanisms. Results demonstrated that the addition of walnut shell reduced tensile strength and maximum elongation, while maintaining acceptable stiffness at intermediate loadings. Thermally, the biocomposites exhibited multi‐stage degradation and remained stable up to approximately 200°C. AE results indicated a transition from ductile to brittle fracture behavior as the reinforcement content increased. In conclusion, PLA/walnut biocomposites present a balanced combination of functional performance and sustainability, making them promising candidates for biodegradable packaging, agricultural applications, and low‐load structural components.