Rubber---Scientific terms

What is the scientific name for the rubber in auto tires?

[sub]More help for my inventor friend.[/sub]

The most common formulation is a coplymer(two monomers) between styrene and butadiene in a 1 to 3 molar ratio. This is called SB rubber.
A monomer is a single unit of the compound prior to polymerization. The single monomer in polystyrene (packing foam) is styrene.