Atomistic investigation of GFRP composites under chloride environment

Fiber reinforced polymer composites have paved the way for the evolution of the engineering materials. Glass fiber reinforced polymer (GFRP) has become one of the most promising materials among the novel composites due to its low price and high performance. Here, the GFRP composite in investigated by fill atomistic molecular dynamics, which contains the epoxy matrix and amorphous silica substrate. The degradation in chloride environment is revealed through the interfacial interactions, the structural changes of the epoxy matrix and hydrogen bonding in the composites. Compared to dry and aqueous environment, the simulation results show that chloride environment leads to the worst deterioration of interfacial adhesion, which correlates with structural and mechanical degradation of bonded interface, as indicated by the decreased epoxy density close to interface. It is indicated by examining the nano-structures of the interface during the pulling process that the chloride environment hinders the formation of intramolecular and intermolecular hydrogen bonds in the GFRP composites. These findings indicate the deterioration towards bond and matrix is critical in the presence of the chloride environment, which provides the fundamental insight for designing and predicting performance degradation of macroscopic GFRP composites in the marine application.