Cure kinetics and viscosity models for Hexcel 8552 epoxy resin

摘要

Process modelling is an important tool in the development of processes for cost-effective manufacturing of composite structures. Accurate prediction of many of the key material properties required in composites process models such as resin viscosity, elastic modulus and cure shrinkage depend on an accurate knowledge of the cure state of the resin during processing. Furthermore, an understanding of resin viscosity behavior is also required to predict the flow of resin daring the laminate compaction process. In this work, the curing and rheological behaviour of Hexcel 8552 toughened epoxy resin are experimentally determined using a differential scanning calorimeter (DSC) and a parallel plate rheometer, respectively. Cure rate is then modeled using a modified autocatalytic equation that accounts for the shift from a kinetics-controlled to a diffusion-controlled reaction above the glass transition temperature (T{sub}g). For viscosity prediction, a previously-developed empirical model is modified to account for the rapid increase of viscosity at gelation. Both resin curing and viscosity model predictions are compared to experiments for isothermal and dynamic curing conditions. Very good agreement is obtained for both models, particularly for typical cure cycle conditions.