Influence of thermo-oxidative and ozone ageing on the properties of elastomeric magnetic composites

Elastomeric magnetic composites are materials with ferromagnetic fillers as one of the constituents and rubber blend as polymer matrix. Ferrites, as commonly used magnetic fillers, might be able to influence the long-term stability of rubber materials, mainly if they are applied in high concentrations. Therefore, the thermo-oxidative and ozone stability of ferrite as well as ferrite and carbon black filled composites based on natural and butadiene rubber were studied by oven ageing and thermogravimetric analysis. The results revealed that ferrite alone also ferrite in combinations with carbon black influences the properties of evaluated materials in various ways. But the thermo-oxidative stability of prepared composites seems not to be influenced by the amount of ferrite even in case of high magnetic filler contents. From thermogravimetric curves it became evident that the thermal degradation of prepared materials also was not influenced by the doping content of ferrite. The ozone ageing tests demonstrated that the influence of ferrite on the ozone stability of natural rubber as well as butadiene rubber based composites was ambiguous. In case of natural rubber based composites filled with combinations of ferrite and carbon black, it can be stated that the more carbon black rubber materials contain, the better is the resistance against ozone degradation.