Styrene-Ethylene-Butylene-Styrene Thermoplastic Elastomer (SEBS)
Properties and Applications
Styrene-ethylene-butylene-styrene, also known as SEBS, is an important thermoplastic elastomer (TPE) which behaves like rubber without undergoing vulcanization. SEBS is strong and flexible, has excellent heat and UV resistance and is easy to process. It is produced by partial and selective hydrogenating of styrene-butadiene-styrene copolymer (SBS)1 which improves the thermal stability, weathering and oil resistance, and makes SEBS steam sterilisable.2 However, hydrogenation also reduces the mechanical performance and increases the cost of the polymer.
SEBS elastomers are often blended with other polymers to enhance their performance. They are used as impact modifiers for engineering thermoplastics and as flexibilizers / tougheners for clear polypropylene (PP).3 Often oil and fillers are added to lower cost and / or to further modify the properties. Important applications include hot-melt pressure sensitive adhesives, toy products4, shoe soles, and TPE-modified bitumen products for road paving and roofing applications.
Manufacturers & Distributors
1US 2015/0031835, Heterogenous catalyst and Method for Selectively Hydrogenating Copolymer Utilizinbg the Same
2Eliminatiing most or all of the double bonds in the soft phase of the elastomer greatly improves the resistance to thermo-oxidative degradation and unwanted crosslinking.
3F.O.M.S. Abreu, M.M.C. Forte, S.A. Liberman, SBS and SEBS Block Copolymers as Impact Modifiers for Polypropylene Compounds, J. Appl. Poly. Sci., 95,2, 254–263 (2005)
4SEBS can replace PVC in many applications. Formulations typically do not contain plasticizers, whereas soft PVC consists of up to 50% by weight of plasticizers, often phthalate esters, which can leach or migrate to the surface.6