Effect of pineapple peel-derived biochar on the characterization of pineapple leaf fiber reinforced polymer composites for lightweight engineering applications

Abstract In this study, a polyester matrix was used to develop hybrid composites reinforced with pineapple leaf fibre (PALF) and pineapple peel-derived biochar (PPB). Composites with a constant PALF content of 30 wt.% and various PPB contents (0–20 wt.%) were made using hand lay-up technique. The developed composites have been evaluated for their physical, mechanical and thermal properties. The findings indicated that incorporating PPB improved the performance of the composites up to an optimum filler loading of 15 wt.%. The composite PALF-PPB15 had the highest properties of hardness, impact, tensile, flexural and shear strength which were 85 Shore D, 3.1 J, 53.48 MPa, 98.62 MPa and 17.24 MPa respectively. In addition, the water absorption decreased from 5.92 % to 3.88 % and the thermal conductivity and heat deflection temperature were 0.231 W m −1 K −1 and 84.3 °C respectively. The enhanced performance can be attributed to better dispersion of fillers, lower void content, and a stronger fibre–matrix interaction. Nonetheless, further addition of biochar to 20 wt.% resulted in a further decrease in properties as a result of filler agglomeration and void formation. The results highlight the potential of reinforcement from pineapple waste for the fabrication of sustainable high-performance polymer composites for lightweight engineering applications.