Rheological behavior of a bismaleimide resin system for RTM process

The curing properties and rheological behavior of resin systems were studied with DSC analysis and viscometer measurements respectively. A dual-Arrhenius viscosity model and an engineering viscosity model were established to predict the resin rheological behavior of the resin system. The two viscosity models were compared. The results show the two models are both suitable to predict the viscosity in the mould-filling stage in resin transfer moulding. However, the engineering model provides a more accurate prediction of the viscosity near the gel point. The effectiveness of the engineering viscosity model is verified both in isothermal and non-isothermal conditions. The limitation of the engineering model is that it cannot be used to predict the viscosity after crosslinking of the curing system. The engineering viscosity models can be used to predict the processing windows of different processing parameters of RTM process, which is critical for the simulation and optimization of composite manufacturing processes.