The effects of carbon nanofiber on the mechanical properties of glass/coir fiber reinforced polyester hybrid composites

Glass and coir fiber hybrid composites were characterized for the addition of 0.1, 0.5, and 1 wt% functionalized fCNFs produced from waste coal fly‐ash and were used also as secondary reinforcements for producing both glass and coir fiber composites. Before choosing the hybrid composites fabrication parameters, an optimum fiber mass fraction of glass and coir fibers were obtained by fabricating and mechanically testing the composites specimens with mass fraction of 24, 32, and 40 wt% for glass and 10, 15, and 20 wt% for coir fibers, respectively. From the test results, the glass fiber composites with 32 wt% and coir fiber composites with 15 wt% were found to be the most suitable mass fraction for fabricating the hybrid composites. Based on the functionalization results, the surface‐treated CNFs for 6 hr in an acid solution were the best secondary reinforcement in fabricating glass and coir fiber hybrid composites. The hybrid composites testing results showed that both glass and coir fiber hybrid composites reinforced with 0.5 wt% functionalized CNFs were better than those of 0.1 and 1 wt% of CNFs. At higher weight fraction of 1 wt% CNFs, agglomerations could not be prevented and this led to poor mechanical properties. It could also be concluded that the functionalization of these CNFs improved their dispersion within the matrix and resulted in better mechanical properties. One of the future recommendations is that the researchers must focus on utilizing the waste products for producing carbon nanoparticles which could further be used for manufacturing hybrid composites. POLYM. COMPOS., 39:318–328, 2018. © 2016 Society of Plastics Engineers