Styreneblockethylenebutyleneblockstyrene

Styrene-block-ethylene-butylene-block-styrene, often abbreviated as SEBS, is a type of thermoplastic elastomer. It is a block copolymer composed of three distinct blocks: a central block of randomly polymerized ethylene and butylene units, flanked by two end blocks of polystyrene. This unique structure gives SEBS its characteristic properties, combining the elasticity of rubber with the processability of plastics.

The polystyrene end blocks provide rigidity and strength, acting as physical cross-links at room temperature. The ethylene-butylene midblock provides flexibility and elasticity. When heated above the glass transition temperature of polystyrene, the material softens and can be processed like a thermoplastic. Upon cooling, the polystyrene domains solidify, forming a network that imparts elastomeric properties.

SEBS is known for its excellent weatherability, UV resistance, and chemical resistance. It also exhibits good low-temperature flexibility and a wide service temperature range. It is generally considered safe for food contact applications and medical devices due to its low toxicity.

This material finds widespread use in various applications. It is commonly employed in the manufacture of soft-touch grips for tools and consumer goods, seals and gaskets, medical tubing, adhesives, and as a modifier for other plastics to improve their impact strength and flexibility. Its versatility and favorable properties make it a valuable material in numerous industries.