ABSTRACT
This chapter reviews styrene-butadiene rubber (SBR), by far the world's foremost synthetic rubber and easily available world-wide. This is because practically all automotive tires use SBR, especially in the tread. The great majority of SBR is made by emulsion polymerization. One of the properties affected by the polymerization temperature is the tensile strength of the copolymer. In continuous emulsion polymerization of styrene and butadiene to make SBR, the various ingredients are charged continuously to reactors in series. Very popular forms of modified SBR are the masterbatches made with oil, with black, or with oil and black. Compared to natural rubber, SBR is somewhat harder to break down in mixing for easier incorporation of other components of the compound. Although solution-polymerized SBR has been available for some years, only comparatively recently has much interest been shown in its use. Solution SBR is available as dry or oil-extended rubber.
