Preparation and properties of coir fiber-reinforced ethylene glycol dimethacrylate-based composite

Abstract

The mechanical properties of the coir fibers were evaluated in this study. Tensile strength (TS), Young’s modulus (YM) and elongation at break (Eb%) of virgin coir fibers were found to be 152 MPa, 5.3 GPa and 36%, respectively. Coir fibers were treated with ultraviolet (UV) radiation and were found to improve the mechanical properties significantly. Coir fiber-reinforced ethylene glycol dimethacrylate (EGDMA)-based composite was prepared and characterized. The surface of the coir fibers was modified with monomer EGDMA under UV radiation. Soaking time, monomer (EGDMA) concentration and radiation intensities were optimized over mechanical properties. The highest values of TS, YM, Eb and polymer loading (PL) were found for 50% EGDMA at 125th pass of UV radiation for 7 min soaking time. Pretreatment with UV radiation on the coir fiber was found to be more effective for the increment of its mechanical properties. The surface of the fiber was also mercerized (alkali treatment) using aqueous NaOH solutions (5–50%) at varied time and temperature. It was found that TS of the mercerized composites increased with the increase in NaOH solutions (up to 10%) and then decreased. The composites made using mercerized fibers treated with EGDMA showed further increase in TS. Pretreatment with mercerization + UV treatment of coir fiber showed significant improvement in the mechanical properties of the coir fiber-based composites.