Investigation of the cure kinetics and thermal stability of an epoxy system containing cystamine as curing agent

2,2 '-Dithiobisethanamine (cystamine), an aliphatic diamine containing exchangeable disulfide bonds, was used as the curing agent for epoxy resin. The dynamic curing kinetics and thermal stability of the epoxy/cystamine system were investigated by DSC and TGA analysis. Applied the Malek method, the Sestak-Berggren autocatalytic equation was selected to describe the cure kinetics of the epoxy/cystamine system. The results showed that the Sestak- Berggren equation is in good agreement with the experimental data. The activation energy of the curing reaction was 56.2 and 53.6 kJ mol (-1), respectively, calculated by Kissinger and KAS models. Also, the glass transition temperature for the epoxy/cystamine system was slightly than that of the commonly used epoxy-diamine systems. Moreover, the thermal degradation of the cured epoxy/cystamine network was observed at temperatures above 283 degrees C. Further, the results obtained from the epoxy/cystamine system were compared with those obtained from the epoxy/diethylenetriamine system. All the above results suggest that cystamine has the potential to be used as the curing agent for epoxy systems.

Automated summary

The study found that cystamine as a curing agent for epoxy resin was well described by the Sestak-Berggren autocatalytic equation, with activation energies of about 56.2 and 53.6 kJ mol(-1), and a slightly lower glass transition temperature compared to other systems. Thermal degradation of the cured epoxy/cystamine network occurs above 283 degrees Celsius.