Antioxidant effects on curing/processing and thermo-oxidative aging of filled nitrile rubber

Abstract

Since anti-aging agents are widely used to improve the heat resistance of magnetic composites, the exploration to the effect of anti-aging agents on the magnetic composites is of great significance to the practical application. In this work, nitrile rubber/iron oxide/zinc dimethacrylate composites were prepared by incorporating various commercial anti-aging agents which are commonly used. It is found that the cross-linking density of the composites was obviously reduced after adding the anti-aging agents, which had a great influence on the mechanical properties. For example, compared with the composite without antioxidants, after adding the anti-aging agent DAPD, the elongation at break of the composite increased by ~ 4-fold, the hardness of shore A decreased by ~23°, and stress at 100% elongation decreased by ~4.5 MPa. Furthermore, the addition of the anti-aging agents was beneficial to promote the relative slip between rubber molecular chains and internal lubrication of the rubber compounds, thus improving the processing performance of the composites. Finally, the thermo-oxidative aging of composites with different anti-aging agents at different time and temperatures was evaluated. This paper provides constructive suggestions to further modify and select the antioxidants for the magnetic composites.