Experimental Characterization of a Curing Thermoset Epoxy-Anhydride System: Analysis of Time Sweep Data for Viscoelastic Cure-Temperature-Time Superposition
In this work, a potentially more efficient method for the generation of the cure-temperature-time master curve, using frequency-time-sweep experiments, is discussed in the context of a curing thermoset epoxy resin-anhydride system. The proposed methodology involves the characterization of the curing resin in the frequency domain rather than the time domain. The successful implementation of this methodology can facilitate capturing the evolution of the resin modulus covering the entire duration of cure (both before and after the onset of gelation), which is not feasible with stress-relaxation based approaches. The experimental method and the analytical procedure adopted for generating the master curve are described in detail. Several challenges involved in the successful implementation of the proposed method are identified, and recommendations to remedy these potential problems, in order to generate a theoretically consistent interpolatable cure-temperature-time master curve, are presented.