Latent Curing, Chemorheological, Kinetic, and Thermal Behaviors of Epoxy Resin Matrix for Prepregs
Yeong Jae Kim, Sung Ho Choi, Seong Jae Lee, Keon‐Soo Jang
Abstract
Epoxy prepregs are extensively exploited in a myriad of applications. Thermal, rheological, and curing behaviors of epoxy resins are important for the impregnation of carbon fibers into the resin. The demand for latent curing properties in the field of epoxy prepregs is more intense than in the field of epoxy resins owing to the impregnation process at high temperature. In this study, we examined the thermal, rheological, kinetic, and curing properties of a latent curable epoxy resin matrix for prepregs by tailoring the material composition and deactivators (latent curing additives). Four organic and inorganic deactivators were found for the epoxy/amine/tertiary amine system. The incorporation of fumed silica, boric acid, benzoic acid, and triethyl borate (TEB) induced latent curing behaviors of the epoxy resin matrix. TEB was found to be an excellent deactivator, showing no reaction at 60 °C for 1 day and increasing the exothermic reaction peak temperature. The systematically investigated epoxy matrix for prepregs with optimum composition can be used for aerospace and automotive applications.