Mechanical property improvement of oil palm empty fruit bunch composites by hybridization using ramie fibers on epoxy–CNT matrices

Abstract Oil palm empty fruit bunches (OPEFBs) can be transformed into composite boards with higher selling value when their cellulose is used as a fiber. Manufacturing composites with hybridization techniques can improve their properties. This study combined OPEFBs and ramie fibers in an epoxy–carbon nanotube (CNT) matrix. The proportion of OPEFBs and ramie fibers was varied (3:7, 5:5, and 7:3), with a total fiber content of 10% by volume and a matrix of 90% by volume. Alkali treatment using NaOH solution was applied to the fiber to remove impurities from the surface. CNTs were functionalized using nitric acid followed by hydrogen peroxide to improve compatibility. Surface treatment was conducted on fibers and CNTs to increase the bonds between these components in the composite material. The hybridization of OPEFBs/ramie fibers improved the tensile strength in the 3:7TR, 5:5TR, and 7:3TR composites by 127, 37, and 12%, respectively, compared to the 10T composite. The flexural strength of the 5:5TR hybrid composite increased by 120%, and that of the 3:7TR and 7:3TR composites increased by 83% against the 10R composite. The 3:7TR hybrid composite showed the best mechanical properties.