Understanding thermo-oxidative degradation of polyacrylic ester elastomer and its nanocomposites through molecular dynamics simulation and experiments

Abstract Acrylic rubber is a special class of synthetic rubber with outstanding hydraulic oils, engine oils and transmission fluids resistant properties. A further improvement in the heat resistance of the elastomer is required in view of the stringent application requirements. This can be achieved by adding suitable nanofillers inside the elastomer matrix to enhance the degradation resistance of polyacrylicester elastomer under thermo-oxidative condition. However, polymer recycling and sustainability require knowledge of degradation behaviour. Reactive molecular dynamics simulations were executed on a polyacrylicester model compound composed of ten monomer units (ACM10) to study its thermal decomposition in the presence of oxygen. With the addition of model silica and graphene oxide, initial as well as final decomposition temperature was improved, while the rate of degradation was reduced for ACM10. The simulation method gave an insight into the degradation pathway of ACM10 by analysing different fragmented products like alkenes, alkyl radicals, and carbon dioxide. Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) technique was employed to verify the results further. The activation energy of degradation calculated both from the simulation and thermogravimetric analysis were also comparable. This investigation would assist to understand and enhance the heat-resistant properties of different elastomers for industrial applications.