Effects of moisture exposure on the crosslinked epoxy system: an atomistic study

Abstract

Diffusion of water into the polymer structures can influence the structure and properties of the polymers. The absorbed water is believed to degrade the strength and properties of the polymers and hence it is important to study how it affects the thermal and mechanical properties of the polymers. In this report, the effects of moisture on the epoxy network and its properties are studied. The epoxy in this work is considered as the result of the curing of diglycidyl ether bisphenol-A (DGEBA) with JEFFAMINE®-D230 hardener. Several structural and dynamics analysis has been conducted to investigate the effects of the ingress of water into the polymer structure. The significant changes in the epoxy structure as a result of introducing water to the system are observed. The molecular structure has been monitored as it underwent the water uptake process. The variation of the atomic correlations due to the exposure to the moisture is reported. Moreover, the effects of adding water on the glass transition temperature and Young's modulus is revealed. The changes in the properties are explained by the results obtained from monitoring the molecular structure.