MODELING OF GELATION AND VITRIFICATION POINTSFOR POLYMER COMPOSITES USING SHEAR RHEOMETRY

摘要

This paper presents modeling of the gelation and vitrification points for two commercial carbonrnfiber prepregs (977-2 UD and E7K8 PW). First, different definitions for the gelation andrnvitrification points were studied and, based on each definition, these points were obtained fromrnthe data provided by an Encapsulated Sample Rheometer (ESR) during isothermal curing of eachrnprepreg. The definition that best fits the gelation point for each prepreg was selected based on thernbehavior of each prepreg during cure. Finally, the gelation and vitrification points were modeled.rnThe gelation and vitrification data and models were used in the Time TemperaturernTransformation (TTT) diagrams. The TTT diagrams and the associated models can be used as arncure map to directly estimate the material state during cure in order to address the issuesrnresulting from uncertainties in composite processing.