Effect of Nano-Confinement On Cure Kinetics of Highly Cross-Linked Epoxy: A Molecular Simulation Study

Recent experiments have reported that the cure reaction for cross-linked materials in nano-porous glass is significantly faster compared to that in the bulk. The molecular mechanisms underlying this observation are not entirely clear. In this work, we have used molecular simulations to study the nano-confinement effect on the kinetics of cure reaction for highly cross-linked epoxy. The chemical system to be studied consists of two types of molecules: epoxy monomer and cross-linker. We have implemented a coarse-grained model to carry out reactive molecular dynamics simulations of the autocatalytic reactions of these two molecules. The kinetics of the reaction in the bulk was compared with that in a cylindrical channel. Our simulations show that the rate of reaction is significantly enhanced in cylindrical channel as compared to that in the bulk; these observations agree well with the experimental reaction kinetics. The nano-confinement effect on cure kinetics will be characterized in terms of the size of the cylindrical channel and collision frequency of molecules.