Figure 4.
The horizontal axes show temperature from 50 to 250 degrees Celsius, and the vertical axes show heat flow in watts per gram with exo up. Panel a shows an E C O to D D S A ratio of 1 to 1.5, with heat flow increasing gradually from 50 degrees Celsius, rising sharply to a peak near 165 degrees Celsius, then decreasing sharply by about 190 degrees Celsius and remaining low to 250 degrees Celsius. Panel b shows pre-curing times of 60, 90, and 120 minutes. All samples increase to peaks between about 160 and 170 degrees Celsius, with 90 minutes highest, 120 minutes slightly lower, and 60 minutes lowest, then decrease sharply near 180 degrees Celsius and rise slightly towards 250 degrees Celsius. Panel c shows pre-curing times of 60, 90, and 120 minutes with curing for 30 minutes. Heat flow decreases gradually from 50 to 250 degrees Celsius, with 90 minutes remaining highest, 120 minutes in between, and 60 minutes lowest.(a) Nonisothermal DSC thermogram of the top layer formulation; (b) nonisothermal DSC curves of the top layer formulation after being precured at 120°C for different durations; and (c) nonisothermal DSC scans of the films cured by a two-stage curing process