Evolution of F-S-SBR In Silica Tire Tread Formulation

Silica tread performance was studied in a two variable/ two level designed experiment.  The two variables were polymer functionality and mix method.  The first polymer was a functionalized solution styrene butadiene rubber (F-S-SBR).  The second polymer was a non-functionalized solution styrene butadiene rubber (S-SBR).  In this experiment, the Dow SE SLR-4602 was compared to the Lanxess Buna VSL 5025-0-HM (S-SBR).  Secondly, two mix methods were compared.  These methods were basically with and without extended mixing time in the first and second passes.  The four compounds were tested by time domain NMR, aged and unaged tensile properties, DMA temperature sweep, and DMA strain sweep.  Tread performance predictors were measured including wet traction, rolling resistance, and tread wear for each variable (polymer functionality and mix method).