Flexural Properties of Surface-Modified Sisal Fiber-Reinforced Polyester Resin Composites

Abstract

This study includes untreated sisal fibers, fibers that had been mercerized using 0.06 M NaOH and fibers cornified at 100°C in different volume fractions used as reinforcement into a general purpose unsaturated polyester resin matrix. Untreated sisal fiber-reinforced polyester resin displayed the most significant gain in flexural strength with a Modulus of Rupture of 79.32 Mpa at 2% fiber volume fraction, which represented a 296.65% increase compared to unreinforced polyester resin. Cornified sisal fiber-reinforced polyester resin had the least significant gain in flexural strength with a maximum Modulus of Rupture of 49.71 Mpa at a 1.2% fiber volume fraction, which represented a 142.8% increase in flexural strength compared to the unreinforced polyester resin specimen. These results show that the untreated sisal fiber reinforcement could withstand the thermal effect of the exothermic curing of unsaturated polyester resin better than the surface-modified sisal fibers.