Determination of activation energy and preexponential factor of thermoset reaction kinetics using differential scanning calorimetry in scanning mode: Influence of baseline shape on different calculation methods

摘要

Differential scanning calorimetry (DSC) is one of the most used methods for kinetic studies of thermoset cure reactions. The basic assumption made in this technique is the proportionality between the heat generation rate and cure reaction rate. To have access to the heat generation rate that provides information about reaction kinetics, one must know the baseline under the measured curve. Various methods of baseline construction are described and recommended, but most thermoset cure kinetic studies only use a straight line between the exothermal peak start and the end. The influence of changes in the sample's heat capacity is rarely taken into consideration. The use of data obtained with this type of baseline to determine kinetic parameters can lead to significant errors. DSC thermograms in the scanning mode are simulated for two epoxy-amine type systems of known cure kinetic and thermophysical characteristics. Simulated thermograms are analyzed using a straight baseline, and different parameter estimation techniques are applied to the resulting data to characterize the cure reaction. The results are compared with real values. (C) 2000 John Wiley & Sons, Inc. [References: 25]