The aging properties and phase morphology of silica filled silicone rubber/butadiene rubber composites

Large amounts of antioxidants are used in unsaturated rubber composites, such as butadiene rubber (BR), which would inevitably cause surface discoloration. In this study, silicone rubber (VMQ) was blended with BR for improving its anti-aging properties. It was found that VMQ/BR exhibits better thermal oxidative aging and ozone aging resistance than BR, especially for 20/80 VMQ/BR. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were applied to characterize the phase morphology of VMQ–silica master-batch/BR, indicating that VMQ phases present island-dispersed domains of circular and elliptical shapes in the BR matrix, and silica particles mainly exist at the interface between BR and VMQ phases. These are two decisive factors for the improved aging properties of VMQ/BR.