CURE PROCESSING MODELING AND CURE CYCLE SIMULATION OF EPOXY-TERMINATED POLY(PHENYLENE ETHER KETONE) .2. CHEMORHEOLOGICAL MODELING

Chemorheology and corresponding models for an epoxy-terminated poly(ph enylene ether ketone) (E-PEK) and 4,4'-diaminodiphenyl sulfone (DDS) s ystem were investigated using a differential scanning calorimeter (DSC ) and a cone-and-plate rheometer. For this system, the reported four-p arameter chemorheological model and modified WLF chemorheological mode l can only be used in an isothermal or nonisothermal process, respecti vely. In order to predict the resin viscosity variation during a stepw ise temperature cure cycle actually used, a new model based on the com bination of the four-parameter model and the modified WLF model was de veloped. The combined model can predict the resin viscosity variation during a stepwise temperature cure cycle more accurately than the abov e two models. In order to simplify the establishment of this model, a new five-parameter chemorheological model was then developed. The para meters in this five-parameter model can be determined through very few rheology and DSC experiments. This model is practicable to describe t he resin viscosity variation for isothermal, nonisothermal, or stepwis e temperature cure cycles accurately. The five-parameter chemorheologi cal model has also successfully been used in the E-PEK systems with tw o other curing agents, i.e., the diamine curing agent with the additio n of a boron trifluride monoethylamine (BF3-MEA) accelerator and an an hydride curing agent (hexahydrophthalic acid anhydride). (C) 1997 John Wiley & Sons, Inc.