11. Isora Fibre: A Natural Reinforcement for the Development of High Performance Engineering Materials

In this chapter, the technical potential of a natural fibre namely “ISORA” has been examined as an effective reinforcing material to design and manufacture high performance eco friendly composites in various polymers like natural rubber, polyester, epoxy resin, etc.; “Isora” a bast fibre separated from the bark of Helicteres isora plant is an important raw material can be used for the preparation of cost-effective and eco friendly composites. Morphology and physical properties of these fibres have been studied. Density and microscopic methods are used to determine the cross-sectional area and diameter of fibre bundles. Surface modification by alkali treatment and silane treatment were tried. Tensile properties of the treated and untreated fibres were determined by density method. The thermal characteristics, crystallinty index, reactivity, and surface morphology of the untreated and treated fibres have been studied by TGA, DSC, DTA, WAXRD, FTIR, and SEM. Average tensile strength of the fibre decreased and density increased to some extent on treatment with alkali and silane. Chemical constituents of the fibre were determined according to ASTM standards. SEM studies showed that as a result of chemical treatment fibre surface becomes rough promoting the fibre matrix adhesion which in turn improves the mechanical performance of the composites. Thermal analysis showed that chemical modification improves the thermal stability of the fibre. The strength of the fibre was theoretically calculated. For the successful design of a composite material using isora fibre and various polymers like natural rubber and thermosets (polyester and epoxy resin) several parameters like fibre aspect ratio, fibre orientation, fibre loading, chemical modification of fibre surface, fibre matrix adhesion that influences the performance of a short fibre composite were studied and optimised.