Application of isothermal and model-free isoconversional modes in DSC measurement for the curing process of the PU system

The dynamic, isothermal, and model-free isoconversional modes of differenti al scanning calorimetry measurement were used to monitor the curing process of the polyurethane system. Conversions obtained from these three methods were in good agreement with one another, indicating that isothermal and mod el-free isoconversional modes can successfully be used for monitoring the c uring process. For the isothermal mode, the highest reaction rate occurred at time zero, and autoacceleration was not observed for this system. From t he model-free isoconversional mode, it was possible to calculate the activa tion energy changes during the curing process. (C) 2001 John Wiley & Sons, Inc.