The effects of carbon nanotubes added polyvinyl alcohol nanofibers on mechanical properties of carbon reinforced composite laminates

This study investigates tensile and flexural behaviors of carbon fiber reinforced epoxy (CFRE) composite laminates strengthened in different weights multi walled carbon nanotubes (MWCNT) with/without polyvinyl alcohol (PVA) nanofiber mats. First, PVA nanofiber mats modified with 1, 3, 5 wt% MWCNT were produced by electro spinning. Characterization of 1, 3 and 5 MWCNT reinforced/unreinforced PVA nanofiber mats was achieved via transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Then, the produced nanofiber mats were placed in the middle of eight-layer twill carbon fabrics by hand layup after carbon composites were produced by vacuum infusion. Three flexural tests were performed in accordance with ASTM D 7264/D standard so that flexural strength properties of the composites and flexural modulus of elasticity can be found. After that, tensile test was carried out in accordance with ASTM D 3039 for the composites to have single axis tensile strength and modulus of elasticity nanofibers. The tensile strengths of PVA nanofiber mats and 1 wt% MWCNT/PVA nanofiber mats reinforced CFRE composites increased by 4% and 34%, respectively when compared to the CFRE composite.