Mechanical, thermal and water absorption properties of Bauhinia Purpurea L fiber reinforced vinyl ester composites

Abstract The core focus of this study is to investigate the impact of Bauhinia Purpurea L fiber (BPF) content (5, 10, 15, 20 and 25 wt.%) on various properties of vinyl ester (VE) based composites manufactured through the compression molding method. The results reveal that the composite added with 20 wt.% of BPFs shows ideal mechanical and thermal characteristics. This composite exhibits the ultimate tensile strength of 44.28 MPa and tensile modulus of 4.93 GPa, whereas the flexural strength and modulus were 46.18 MPa and 5.63 GPa, respectively. In addition, the impact strength and hardness of this composite were 12.2 kJ/m ² and 83.51 (Shore D) respectively. The thermal stability of the composite (from 230 to 452°C) was confirmed with Thermogravimetric analysis (TGA). Differential Scanning Calorimetry analysis (DSC) reveals the high resistance to heat in 20 and 25 (wt.%) BPFs loaded composites with heat flow of 20.057 W/g and 19.296 W/g, respectively. The incorporation of 25 wt.% BPFs into the matrix increased the hydrophilicity of the composites, as confirmed by water absorption testing and contact angle measurements. The cracked surfaces of the samples were investigated through scanning electron microscopy (SEM) to investigate the failure mechanisms. The composite containing 20 wt.% of BPF exhibits advantageous properties, making it suitable for various engineering applications, including lightweight vehicle bumpers, door panels, electrical components, civil structures, and home appliances. Highlights Behavior of BPF/VE composites was assessed through various properties. Mechanical performance of a composite improved as the BPF content elevated. Adding BPF to vinyl ester enhances composites decomposition resistance. Incorporation of BPF reduces the dissipation of heat across the composites. Hydrophilicity is observed for the composites with higher BPF content.