Kinetic analysis of a fast reacting thermoset system

Many thermosets are rapidly mixed and processed to quickly and efficiently effect a bond or produce a protective coating or a finished part. These processes are often characterized by non-linear time–temperature profiles. While it is often desirable to model the cure it can be challenging with such highly reactive systems in rapid processes. Described here is a hybrid approach to determine the kinetic equation for such a system. DSC multiple heating rate, isothermal and simulated process methods were combined with time–temperature superposition methodology to generate a master curve for the chemically controlled cure. Analysis of the master curve showed that it could be described by a second-order kinetic equation, consistent with polyurethane cure and permitting the complete kinetic description of the system.