SEBS & SBS Thermoplastic Elastomers

SEBS, SBS-OE or SBS: which family do you need?

All three are styrenic block copolymers, so they behave like rubber at room temperature yet process like thermoplastics. The differences come from the rubbery mid-block and the oil content:

Still deciding between hydrogenated and standard grades? Our SEBS vs SBS selection guide compares weathering, processing temperature, oil uptake and cost per part.

SEBS and SBS FAQ

What is SEBS elastomer?

SEBS (styrene-ethylene-butylene-styrene) is a styrenic block copolymer made by hydrogenating SBS. Hard polystyrene end blocks hold the chains together, and the saturated ethylene-butylene mid-block gives rubber-like elasticity. Because the mid-block has no double bonds, SEBS elastomer resists heat, UV, ozone and oxidation far better than SBS, and it takes up large amounts of paraffinic oil for very soft compounds.

Is SEBS a rubber or a plastic?

Both, which is why it is called a thermoplastic elastomer. At room temperature the polystyrene domains act as physical cross-links, so SEBS stretches and recovers like vulcanized rubber. When heated above about 100 °C those domains soften, and SEBS melts and flows like a plastic. It needs no vulcanization, can be injection molded or extruded on standard plastics equipment, and sprues and scrap can be reground and reused.

What are the main SEBS applications?

Most SEBS goes into TPE compounds with oil and PP: soft-touch grips, handles and overmolded parts on PP, automotive seals and interior parts, hoses and tubing, and other injection-molded components. Other SEBS applications are medical tubing and bags, hot-melt and pressure-sensitive adhesives, sealants, protective film, oil gels and cable filling, and impact modification of PP and PE. For PP toughening, also compare POE elastomers. See the application table on our SEBS grades page.

When is SBS the better choice than SEBS?

SBS thermoplastic elastomer costs less and is the standard choice for asphalt and roofing modification, solvent and hot-melt adhesives, footwear and indoor rubber goods, where UV and heat aging are not critical. Oil-extended SBS-OE is preferred for soft TPR shoe soles. Choose SEBS for outdoor, heat-aged, low-odor or medical parts. Our SEBS vs SBS selection guide shows the trade-offs.

How does SEBS compare with silicone?

SEBS compounds cost less, process on ordinary injection and extrusion lines, bond to PP in two-shot molding and are recyclable. Silicone rubber works over a much wider temperature range and keeps its compression set at high temperature, but it must be cured and cannot be remelted. For parts that stay below roughly 100 °C, SEBS is often the lower-cost option; for heat-resistant seals in engines or repeated steam sterilization, silicone or TPV may fit better. See TPV vs TPE.

Are you an SEBS manufacturer or an SEBS supplier?

SYCHEM TECH is an SEBS supplier based in Shenyang, China, not a producer. We supply hydrogenated SEBS, SBS and SBS-OE grades from established producers and help you match the grade to your compound, adhesive or modification target. Tell us your application and hardness or oil level, and we will email the TDS and arrange a sample. Contact our team or write to info@sychemtech.com.