The influence of the styrene content and features of the molecular structure of solution-polymerised styrene butadiene rubber on the service properties of tread rubbers

摘要

Close attention is currently being paid to improving the service characteristics of tyres in which the tread formulations are based on solution-polymerised styrene butadiene rubbers (SSBRs). This is primarily due to the constantly increasing requirements concerning the safety of motor vehicle transport. To achieve the required properties of tyres, researchers are optimising the compositions of formulations and using different grades of SSBR. Generally, synthetic rubber manufacturers are offering users a range of styrene butadiene copolymers that differ in characteristics, including their content of styrene units [1-3]. This is due to the fact that the comonomer ratio in the polymer chain largely determines the properties of semiproducts and end products. An increased styrene content improves the processing properties of rubber mixes but at the same time leads to a reduction in rebound resilience and wear resistance and to an increase in heat build-up and wet road holding of rubber compounds. It is customary to assume that, in tyre rubber production, the optimum bound styrene content ranges from 1 8 to 25 wt% [4].