Graphene-based aramid/epoxy nanocomposites for ballistic protection

Abstract

Graphene has excellent mechanical properties including high Young's modulus, high tensile strength and fracture toughness, which make it an ideal candidate as fillers for nanocomposite materials. Most of the researches on epoxy/graphene nanocomposites are aimed at exploiting the remarkable mechanical enhancement effect of the graphene coupled with the possibility of introducing further functionalities, such as electrical conductivity or thermal stability. In this research, graphene nanoplatelet (GNP) was selected as the nanofiller for the manufacture of Twaron®/epoxy composites. Different factors in the composite production process, including the particle dispersion methods, composite fabrication methods, GNP loading and number of fabric reinforcement layers, were investigated for the ballistic performance. Optical microscopy was applied with the assistance of public domain software ImageJ® for the examination of GNP dispersion state with different shear mixing speed and duration. An effective dispersion with a 0.8363 dIndex was achieved at 3000 rpm for 1 hour. Perforated ballistic impact tests were carried out to examine the energy absorption capacity of GNP/Twaron®/epoxy composites. The failure mechanisms of nanocomposites were studied on a macro level by a high speed camera and on a micro level by scanning electronic microscopy (SEM) respectively. The increase of energy absorption for composite panels was up to 23.56%, which was achieved by the addition of 0.5 wt % GNP in epoxy resin matrix by vacuum assisted hand lay-up method. The composite panels fabricated by vacuum assisted hand lay-up method have a slightly better energy absorption value than that produced by vacuum assisted resin infusion method. The energy absorption efficiency with 0.1 wt % GNP loading for 16-layer composite sample is lower than that of 8-layer composite sample. In this research, an improved ballistic performance was obtained with the involvement of GNP in epoxy matrix for all samples, which provides a novel reinforcing strategy for the construction of future composite body armour.

Date of Award	31 Dec 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Xiaogang Chen (Supervisor) & Constantinos Soutis (Supervisor)