Mechanical and Thermal Properties of PET-HDPEb-rk Hybrid Composites from Kenaf and Rice husk Fibre; Reinforced with PETand HDPEb Blend.

Plastics have become indispensable in the automotive industry, and the pursuit of innovative materials is crucial for advancing automobile design. Hybrid composites, characterized by a synergistic combination of mechanical properties and environmental considerations, offer a promising avenue for surpassing the performance of natural single-fibre-reinforced composites. This study focuses on the development of PET-HDPEb-rk hybrid composites through a compression moulding process, utilizing a resin blend comprising Polyethylene Terephthalate (PET), High-Density Polyethylene Blow (HDPEb), and a blend of rice husk and kenaf fibre (rk) in a 70:30 % ratio. Scanning Electron Microscopy (SEM) analysis elucidates the improved dispersion and interfacial adhesion between the rice husk-kenaf fiber (rk) particles and the polymer matrix. Notably, the composite with a 30 % HDPEb blend exhibits commendable mechanical properties, including a tensile strength of 350.19 MPa, elongation at break of 9.92 %, impact strength of 0.228 J/m2, average hardness of 64.8 Hv, flexural strength of 70.43 MPa, flexural modulus of 2838.86 MPa, and an initial decomposition temperature of 693.50 oC, with a final maximum rate of decomposition reaching 800 oC. However, a critical concentration is identified with the 30 % PET/HDPEb blend, showcasing superior properties across various analyses. This concentration demonstrates enhanced mechanical properties attributed to a more uniform dispersion and improved interfacial adhesion, providing valuable insights for optimizing filler dispersion and interaction with the matrix. These findings contribute to a comprehensive understanding of PET-HDPEb-rk hybrid composites, emphasizing the significance of tailored material design for achieving improved mechanical and thermal performance. The results of this work extend to diverse applications, particularly in the automotive industry, where enhanced materials are sought for applications such as replacement parts and car bumpers. The presented insights guide future endeavours in designing hybrid composites with superior mechanical and thermal characteristics, paving the way for sustainable and high-performance materials in automotive engineering.