Master Curves of Viscoelastic Coefficients of Matrix Resin

Based on TTSP, the master curve of viscoelastic behavior versus reduced time at a reference temperature is constructed by shifting the measured data at elevated temperatures along the log time axis (horizontal axis). However, the measured data at elevated temperatures are not superimposed smoothly and solely by horizontal shifting. In this chapter, the applicability of modified TTSP with vertical shift and horizontal shift to predict the long-term viscoelastic behavior of thermosetting resin is assessed experimentally. Furthermore, a rapid and simplified determination method using frequency multiplexing dynamic mechanical analysis (DMA) is proposed to elucidate the long-term viscoelastic behavior of amorphous resin. Short-term viscoelastic behavior is measured using DMA under various frequencies and temperatures. The automatic shifting method is proposed to obtain a smooth master curve and accurate time–temperature shift factors. The validity of the simplified determination method is discussed by comparison of the creep compliance master curves obtained from DMA and creep tests.