Flammability, Thermal Stability, and Mechanical Properties of Wood Flour/PC/HDPE Hybrid Biocomposites

In this study, researchers aimed to enhance the properties of wood flour/high-density polyethylene (HDPE) biocomposites by incorporating polycarbonate (PC). To improve the thermal stability of wood flour, boric acid treatment was employed. The treated wood flour was then blended with PC and HDPE to create hybrid polymer biocomposites. The resulting materials were characterized for their chemical structure, microstructure, and properties. The findings revealed that PC was uniformly distributed within the polyethylene matrix as micro- or nanoparticles. By adding PC, the thermal stability of the composites increased, with a 6.7% increase in char residue rate at a PC content of 28%. PC particles acted as nucleating agents for the crystallization behavior of the biocomposites, similar to other nanoparticles. Consequently, the crystallization temperature of the composites increased with increasing PC content. However, the addition of PC did not alter the crystallinity of the composites. Furthermore, the addition of PC reduced the heat release rate during combustion. The tensile strength and modulus of elasticity of the composites increased by 27.7% and 91.1%, respectively. In addition, the flexural strength and elasticity increased by 22.7% and 53.8%, respectively. The creep strain of the composites decreased gradually with increasing PC content, indicating improved anti-creep properties due to the presence of PC. In conclusion, through hybridization and fire retardancy enhancement, the strength, thermal stability, and fire resistance of wood fibers were improved in the resulting biocomposites.