Development of kinetics sub-model of cyanate ester-based prepregs for autoclave molding process simulation

Autoclave molding of prepregs is an established fabrication method to produce composite components to be used in the aerospace industry and elsewhere. The process involves the excess resin to flow out and curing of the resin. The process model simulation, which is very effective to optimize the process parameters and laminate properties, requires various sub-models to account for resin flow and resin curing. This work focuses on the curing behavior and development of kinetic sub-model of a quartz fabric prepreg impregnated with cyanate ester-based resin. Differential scanning calorimetry (DSC) in both dynamic and isothermal modes has been used for the study. The dynamic study reveals that two distinct reaction mechanisms were involved during curing. The dynamic study data is used to obtain the activation energy using model-free iso-conversional method. The kinetic expression obtained using the isothermal DSC scan data is able to predict the complexity of the overall reaction which can be described by nth-order reaction kinetics for the initial phase of reaction followed by the autocatalytic reaction kinetics.