Effect of Epoxy Resin Concentration on Some Mechanical Properties of Carbon Fabric/ Nitrile Rubber Reinforced Composites

Abstract

Carbon fiber reinforced polymer composites (CFRP) are widely used in variety of applications such as flexible aerodynamic surfaces on aircraft, under water flexible vehicles, flexible robotic skeletons and engineering applications. Epoxy resins (ER) are usually employed as the polymeric matrix, in which the fabric laminates are embedded. Although Carbon fabric/resin composites possess outstanding mechanical performance and good process-ability, however, ER are relatively brittle which causes a major problem for the performance of the final structure. In our present study, a woven carbon fiber reinforced polymer composite, with nitrile-butadiene rubber (NBR) as the polymeric matrix were fabricated by hand layup method followed by compression molding. Different concentrations (5,10,15 and 20 part per hundred, phr) of an ER were added to the NBR formulations and compared with similarly-processed CFRP reference material produced without NBR. Various static and dynamic mechanical properties were examined experimentally. The results revealed that CFRP composite containing 10 phr epoxy resin showed significant improvement in the impact strength and flexural strength due to the good energy absorbing of NBR. In addition, tensile strength decreased while elongation at break percentage increased because of high strain capability and elastic recovery of the nitrile rubber. The dynamic mechanical test results such as tan delta, glass