High-temperature degradation of butadiene-based model elastomers by reactive molecular dynamics simulation

Thermal degradation of butadiene-based model elastomers was analyzed via a novel reactive molecular dynamics simulation (ReaxFF) method. The molecular simulation was carried out on 40 monomer units connected together. Degradation pathways of both homopolymer and copolymer of butadiene-based model elastomers such as polybutadiene (BR) and poly (styrene-co-butadiene) (SBR) were studied. The evolution of different fragmented products was examined as a function of time and heating rate. The formation mechanisms of different degraded fragments were visualized via the simulation method. The major decomposition products obtained from these model compounds were the monomers and comonomers. Pyrolysis gas chromatography-mass spectrometry (py-GC-MS) analysis was performed on the commercial samples of BR and SBR to verify the simulation results. The results obtained from the reactive simulation were very consistent with the experimental results. The activation energy required for the thermal decomposition of butadiene-based model elastomers were calculated both from the ReaxFF simulation and thermogravimetric analysis (TGA). The results were also in good agreement. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48592.