Cure kinetics and chemorheological behavior of a wind epoxy resin system and its viscoelastic properties reinforced by glass fiber matt with process of vacuum assisted resin transfer molding

In order to investigate the processability of a wind epoxy resin for the vacuum-assisted resin transfer molding (VARTM) process, a differential scanning calorimeter and rheometry instrument were applied to characterize the curing properties and study the chemorheological behavior to obtain a better understanding of the resin system in order to define the implementation of the process. The curing temperature parameters were established along with a cure kinetic model to predict the cure behavior. In addition, the influence of the gelation and vitrification was also examined by rheological methods. No obvious vitrification appeared in the epoxy system and the apparent active energy of the cure reaction calculated by gel time was almost the same as the differential scanning calorimetry result. What is more, the viscoelastic properties of the composite reinforced by glass fiber matt was characterized through dynamic mechanical analysis, and it proved that post-cure was necessary to ensure complete cure and that the stiffness increased several magnitudes after glass fiber reinforcement.