Cure reaction of epoxy resin used for composite aircraft structures

The cure reaction of an epoxy resin that used for composite aircraft structures was studied by isothermal differential scanning calorimetry (DSC). A series of isothermal DSC run provided information about the behavior of cure in a large the temperature range. According to the heat evolution behavior during the curing process, several influencing factors on isothermal cure reaction were evaluated. The results showed that the isothermal cure reaction of this epoxy resin followed autocatalytic reaction mechanism. In the latter reaction stage, the cure reaction became controlled mainly by diffusion. Cure rate was then modeled using a modified Kamal autocatalytic model that accounts for the shift from chemical reaction controlled to a diffusion-controlled reaction. The model parameters were determined by a nonlinear multiple regression method.