A naphthyl-imide-based epoxy resin: Cure kinetics and application in carbon fiber reinforced composites

A novel heat-resistant epoxy resin based on N, N'-bis(5-hydroxy-1-naphthyl) pyromellitic diimide was prepared and its cure kinetics with 4,4-diaminodiphenysulfone (DDS) was investigated by differential scanning calorimetry (DSC) under non-isothermal and isothermal conditions. Under non-isothermal condition, the effective activation energy calculated from the advanced isoconversional method (AICM) varies with curing conversion, which is different from that obtained by Kissinger's model. This should be attributed to the formation of highly crosslinked network later in the curing stage. The isothermal curing process at different temperatures could be well fitted by Kamal's model in the initial curing stage but deviates subsequently. The deviation is corrected by introducing a diffusion factor in Kamal's model. In addition, the naphthyl-imide epoxy resin is used to prepare carbon fiber reinforced composites and their applications were explored. The composites exhibit a high glass transition temperature, low moisture absorption, sufficient flame retardance and especially very low tensile strength loss at high temperature.