Theoretical Studies of Mechanisms of Epoxy Curing Systems

The epoxy resin market is faced with an ever increasing demand for a “designer” range of properties for the epoxy end-use products. Therefore, it is necessary to obtain a complete mechanism and accurate kinetic model that has predictive capabilities. This dissertation addresses the issue in two sections. The first section is an analysis of systematic theoretical studies on the mechanisms of four main curing reactions, epoxy-amine, epoxy-phenol, epoxy-acid and epoxy-anhydride, at the molecular-level using B3LYP density functional theory. The strength of these mechanistic models is their ability to extrapolate to different reactions that use a particular epoxy resin, a particular curing agent and/or a particular catalyst. The examination of all possible reaction pathways for each curing system can allow us to predict the most preferable pathway in the system and can enable the development of a more accurate kinetic model for the system. In addition, it provides insight into the role of tertiary amines in catalyzing the curing reaction. The second section involves the development of a new kinetic model for the epoxyamine curing system guided by quantum chemistry calculations. This accurate kinetic model for an epoxy-amine curing system has the potential to be applied to other curing systems, solving successfully an industrial issue by quantum chemistry calculation.