Superior flexural, interlaminar- shear and fracture performance of glass fiber/epoxy laminates employing 3-D reinforcement approach: Emphasis on through thickness functionalized CNT alignment

Abstract

Owing to the absence of z-directional reinforcement in laminated glass/epoxy (GE) composites, their performance under out-of-plane normal and in-plane shear loadings are questionable. This article highlights the importance of using an electric field induced nanotube alignment along the z-direction of the laminate using pristine and functionalized CNTs (CNT and FCNT). Use of aligned FCNTs in the GE composite showed best performance as confirmed from a series of mechanical tests, i.e. flexural properties, interlaminar shear strength (ILSS), mode- I and II interlaminar fracture toughness (ILFT). The key finding of this work includes an enhancement in the critical energy release rate under crack opening mode (i.e. GIC) as high as ∼82% in case of A-0.1F-CNT-GE (0.1 wt% aligned FCNT in GE composite) over the control GE composite. Fractographic study reveals various strengthening and toughening mechanisms responsible for the improved mechanical properties of the composites due to alignment and functionalization of CNTs.