Graphene as a prominent antioxidant for diolefin elastomers

Diolefin elastomers are particularly susceptible to thermal oxidative ageing, due to the instability of double bonds and allylic hydrogens when exposed to heat or oxygen. Here we demonstrate that graphene (GE) is a prominent antioxidant for preventing styrene-butadiene rubber (SBR) from thermal oxidation. The antioxidant effect is attributed to its free-radical scavenging and gas barrier abilities, which significantly reduces the free-radical concentration and oxygen permeability of the SBR/GE nanocomposites. Thus, incorporation of graphene strongly suppresses the formation of oxygenic groups and additional crosslinking points, at the same time prolongs the oxidative induction time of the nanocomposites. As a result, the nanocomposites show a lower increase in stiffness and glass transition temperature, and a higher retention ratio of tensile strain and strength, compared to the unfilled and the carbon black filled SBR.