Modification of a Two-Component System by Introducing an Epoxy-Reactive Diluent: Construction of a Time-Temperature-Transformation (TTT) Diagram

Abstract

Curing reactions of a three-component system consisting of an epoxy resin diglycidyl ether of bisphenol A (DGEBA n = 0), 1,2-diaminecyclohexane as curing agent, and vinylcyclohexene dioxide as a reactive diluent were studied to calculate a time-temperature-transformation isothermal cure diagram for this system. Differential scanning calorimetry (DSC) was used to calculate the vitrification times. DSC data show a one-to-one relationship between T g and fractional conversion α, independent of cure temperature. As a consequence, Tg can be used as a measure of conversion. The activation energy for the polymerization overall reaction was calculated from the gel times obtained using the solubility test (58.5 ± 1.3 kJ/mol). This value was similar to the results obtained for other similar epoxy systems. © 2004 Wiley Periodicals, Inc.