Characterisation of Mechanical, Thermal, Flammability and Water Absorption Properties of Bamboo Fabric Reinforced Polymer Composite Materials

Abstract

Natural Fiber Reinforced Polymer Composites have been used immensely in low load bearing applications such as leaf springs, bumpers and boat hulls. Natural fibers are known for their bio-degradability, specific strength and stiffness and ease of extraction. In present work, Plain weave and Twill weave bamboo fabric of 125 gsm were used as reinforcements with medium viscous epoxy B-11 resin and AI 1041 bio-based hardener. Fiber weight fraction was maintained at 18% and composite plates of thickness 3.1, 4.3 and 5.4 mm of plain and twill weave composite were used for study. The aim was to study the influence of weave pattern and thickness of composite on the tensile, flexural, izod impact, thermal, dynamic, water absorption and flammability studies. Fourier Transform Infra-Red results showed the presence of cellulose, polysaccharides in fabric, cardanol groups in resin and hydrogen bonding of reinforcement and matrix. X-Ray Diffraction peaks displayed higher intensities for twill weave fabric indicated high amount of cellulose available for bonding. Tensile studies of fabrics showed 7% higher strength for twill weave compared to that of plain weave fabric in warp direction. Twill weave composites with 5.4 mm thickness showed an increase of 12% in tensile strength and 8% increase in stiffness compared to plain weave. Twill weave composite with 5.4 mm thickness showed an increase of 22% in flexural strength and 28% in stiffness compared to plain weave. Izod impact results displayed an increase of 16% in absorbed energy for 5.4 mm thickness twill weave composite when compared with plain weave. Fractography of tensile tested specimens displayed fiber pullouts for plain weave composites and fiber breakage for twill weave composites. Twill weave composites have shown better wettability than that of plain weave. Weave pattern and composite thickness had negligible influence on thermal degradation of composites Thermo-gravimetric analysis showed a higher thermal stability for composites sustainable till 450 ⁰C, compared to their fabrics. Differential Scanning Calorimetry studies displayed melting of composites at 370 ⁰C. Dynamic mechanical analysis indicated an improvement of 1.3 times in storage modulus for 5.4 mm thickness twill weave compared to plain weave composite. Loss modulus showed a 9% improvement for 5.4 mm thickness twill weave compared to plain weave composite. Loss factor showed ii better damping properties for 5.4 mm thickness twill weave compared to plain weave composite. Cole-Cole plot indicated a homogenous interface for 5.4 mm thickness twill weave compared to plain weave composite. Twill weave were effective in hindering water absorption compared to plain weave composites and it was higher at 5.4 mm thickness. Wettability and thickness of composites hindered the burning rate and a 30% reduction was observed at 5.4 mm thickness.