ReaxFF reactive force field for molecular dynamics simulations of epoxy resin thermal decomposition with model compound

• Pyrolysis of epoxy resin was investigated using ReaxFF molecular dynamics.
• The increased heating rate increases the initial reaction temperature.
• The elevated final temperature decreases the initial reaction temperature.
• Both increase in final temperature and heating rate shorten the initiation time.
• The mechanisms and chemical events agree with available experimental observations.

We have performed a series of molecular dynamics simulations (MDSs) to study the thermal decomposition characteristics of epoxy resin. The effects of temperature and heating rate on the evolution of small molecular products were investigated. The initial reaction temperature increased with the raise in heating rate but the elevated final temperature resulted in decrease of it. However, both raise in final temperature and heating rate shorten the initiation time. ReaxFF MDSs results elucidate that the thermal decomposition of epoxy resin is initiated by the cleavage of ether linkage. The main small molecular products found in our simulations include H2O, CO and H2. Three typical types of mechanisms for the formation of H2O and H2 were observed in simulations, respectively, including radical attacking mechanisms, inter- and intra-molecular elimination, e.g. 1,1-, 1,2- and 1,3-elimination. The information on mechanisms and chemical events during the thermal decomposition processes of epoxy resin agree with the results from previous experiments. The agreement of these results with available experimental observations demonstrates that ReaxFF can provide useful insights into the complicated bulk thermal decomposition of organic materials under extreme conditions at the atomistic level.