SBS is a kind of SBCs with the largest output (accounting for more than 70%), the lowest cost and wide application. It is a triblock copolymer with styrene and butadiene as monomers. It has the characteristics of both plastic and rubber, and is called the "third generation synthetic rubber". Similar to styrene butadiene rubber, SBS can contact with water, weak acid, alkali, etc., and has excellent tensile strength, large surface friction coefficient, good low-temperature performance, excellent electrical performance, good processing performance, etc., becoming the largest consumption of thermoplastic elastomer.