Thermo-mechanical characterization of hybrid kenaf/glass polyester laminates: Effects of fiber hybridization and layering architecture

This study investigates the influence of fabric hybridization and stacking sequence on the physical, mechanical, and thermo-mechanical behavior of polyester-based laminates reinforced with glass (G) and kenaf (K) fibers. Using the hand lay-up route, five different four-layer laminates (GGGG, GKGK, GKKG, KGGK, and KKKK) were fabricated. The GGGG laminate demonstrated superior mechanical performance compared to the KKKK laminate. Among the hybrid configurations, the GKKG laminate achieved the highest tensile strength (79.89 MPa), flexural strength (91.39 MPa) and impact strength (53.36 KJ/m 2 ). Dynamic Mechanical Analysis (DMA) results revealed that, the GKGK laminate exhibited a higher storage modulus than KGGK, while the GGGG laminate attained the maximum loss modulus (691 MPa). Conversely, the KKKK laminate showed the highest damping peak (0.271). Thermal stability was further evaluated for GGGG, KKKK, and GKKG laminates. TGA results indicated greater thermal stability for GGGG, while KKKK exhibited earlier degradation, primarily associated with the thermal decomposition of its lignocellulosic constituents. Scanning electron microscopy (SEM) revealed matrix cracking, fiber pull-out, and interfacial debonding as the primary failure mechanisms, while Fourier transform infrared spectroscopy (FTIR) showed chemical interactions between fibers and matrix in the developed composites.