Application of dielectric and thermal analysis to the curing of epoxy resins

Upon studying the application of dielectric analysis (DEA) to techniques for non-destructive on-line measuring of the curing process of epoxy casting resin in molds, it was found that the ionic conduction portion derived from dielectric loss factor was closely correlated to glass transition temperature and resin viscosity. A new study was undertaken using DEA, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and curing volume shrinkage measurement to investigate in more detail the relation between the electrical conductivity of resins and the degree of cure during the curing process. A relation was quantitatively determined between the equivalent resistivity derived from dielectric loss factor and the degree of cure, viscoelasticity and volume shrinkage