Effect of surface treatment on mechanical properties of Calotropis procera natural fiber reinforced epoxy polymer composites

The natural fibers are finding wide application in fiber reinforced polymer composites, which have the ability to replace synthetic fiber like glass fiber which is widely used as reinforcement in fiber reinforced polymer composites to some extent. The natural fibers are environmental friendly and have high specific strengths. The surface treatment to the fibers removes the surface impurities and makes the fiber surface rough. This rough surface facilitates better mechanical interlocking of the fiber with resin improves adhesion and a strong fiber-matrix bond ensured the effective load transfer. The present investigation deals with Calotropis procera fiber reinforced epoxy composites. The Calotropis procera fiber is characterized by very low density, high strength and is also widely available in southern parts of India. The effect of alkali treatment of fiber on the mechanical properties was investigated. The alkali treated fibers showed higher tensile strength, modulus and elongation, compared to untreated fiber. The composites are fabricated by reinforcing untreated and alkali treated Calotropis procera fibers in epoxy matrix respectively. The mechanical test results indicate increase in mechanical properties of alkali treated Calotropis procera fiber reinforced epoxy composites such as tensile strength, flexural strength, impact strength and hardness, compared to untreated Calotropis procera fiber reinforced composites.