Synergistic reinforcement of HDPE biocomposites with kaolinite nanoparticles and alfa fiber: A path toward enhanced performance

This study developed sustainable, cost-effective hybrid composites using high-density polyethylene (HDPE) reinforced with kaolinite particles (KP) and alfa short fibers (ASF) in varying volume fractions (15/0, 10/5, 7.5/7.5, 5/10, 0/15). Injection-molded composites were analyzed for mechanical, thermal, and rheological properties, revealing significant improvements in Young’s modulus (up to 61.60%) with KP and ASF additions. Hybrid composites (7.5:7.5 and 10:5) showed superior elasticity, while the 5:10 formulation achieved the highest storage modulus of 1874 MPa, outperforming pure HDPE (1035 MPa). Thermal analysis indicated stable KP-rich composites and progressive crystallization disruption with increasing filler content. To align experimental and theoretical results, the Young’s modulus for KP and ASF was estimated at 5000 MPa and 8500 MPa, respectively. The optimal 7.5:7.5 hybrid offered balanced mechanical and thermal performance with enhanced elasticity and reduced energy consumption during processing, demonstrating the potential of these hybrids as renewable, sustainable materials for automotive, construction, and sports applications.