Polymer Engineering and Science, Vol.40, No.2, 418-429, 2000
Chemorheological analysis of an epoxy-novolac molding compound
The chemorheological behavior of an epoxy-novolac molding compound was studied by a combination of differential scanning calorimetry and dynamic rheological measurements. Based on a modified version of Kamal and Sourour's kinetic expression, a procedure aiming at the phenomenological description of cure kinetics was developed. In combination with our kinetic study, an empirical Arrhenius-type expression was adopted for the description of the dependence of complex viscosity on temperature, frequency, and conversion by allowing the pre-exponential factor and the flow activation energy to be frequency- and conversion-dependent. At low conversions (alpha < similar to 0.05), the system behaves approximately as a thermoplastic material; at higher conversions, the rheological behavior of the system was dominated by the extent of cure reaction.