Preparation and chemorheology of epoxy resin film used in RFI process

In order to develop an epoxy matrix resin film used in the low-cost technique of RFI , a new resin film was synthesized with epoxy of E51 , high temperature latent curing agent BF₃-400 and ethylene glycol , through optimizing the ingredient s by the orthogonal design method and controlling the primary reaction degree. The results of the research on its chemorheology show that the least viscosity of this resin film reaches 360 mPa· s , the time of low viscosity below 1000 mPa· s is up to 32 min , and the gel time is 48 min at 130℃ work temperature. The resin film is not sticky and has good flexibility at 25℃ room temperature. Through DSC scanning with different temperature rising rates , the activation energy E_α of the original resin system and that of the resin film were analyzed. It is found that the E_α of the resin film is greater than that of the other one , and increases with the rising of cure degree. Based on the double Arrhenius theory , the prediction function of viscosity and the prediction function of gel time which are both proved to have good applicability by tests were established. According to the viscosity requirement of RFI process , a function for the infusion coefficient is set up , and the optimal theoretical infusion temperature 128. 4 ℃is found.