SEBS vs SBS is one of the first decisions in any styrenic thermoplastic elastomer (TPE) project. Both are styrenic block copolymers (SBCs) with polystyrene end blocks, and both behave like rubber at room temperature yet melt and flow like a thermoplastic. The difference sits in the rubbery mid-block: SBS keeps the unsaturated polybutadiene, while SEBS is hydrogenated to a saturated ethylene-butylene block. That one step decides weathering, heat ageing, processing window and price. This guide compares the two side by side and shows when each one is the better buy.
Short answer: choose SBS for cost-driven, indoor or short-life products and for asphalt and adhesive formulas; choose SEBS when the part sees sunlight, heat ageing or skin contact, or when low odour matters.
How SEBS and SBS differ in structure
In both polymers the hard polystyrene end blocks cluster into small domains that act as physical cross-links, so no vulcanization is needed and scrap can be reground. In SBS the mid-block is polybutadiene, which still carries carbon–carbon double bonds. Those double bonds are where oxygen, ozone and UV light attack, so unstabilized SBS yellows, hardens or cracks over time and degrades if it is held too long at high melt temperature.
SEBS is made by hydrogenating the butadiene block into a saturated ethylene-butylene mid-block. Without double bonds, SEBS keeps its properties through UV exposure, heat ageing and repeated processing, which is why it is often called the weatherable grade of styrenic TPE. The extra hydrogenation step also explains most of the price gap between the two.
SEBS vs SBS comparison table
| Property | SBS | SEBS |
|---|---|---|
| Mid-block | Polybutadiene (unsaturated) | Ethylene-butylene (saturated, hydrogenated) |
| UV, ozone and weathering | Poor without stabilizers | Excellent |
| Heat ageing | Moderate; hardens and yellows over time | Very good |
| Typical compound processing temperature | About 150–190 °C | About 180–220 °C |
| Oil extension | Good; oil-extended SBS-OE grades are available | Very high; high-molecular-weight grades accept well over 100 phr of paraffinic oil |
| Compression set when warm | Higher; the mid-block softens and ages | Lower; holds its shape better in warm service |
| Melt stability and regrind | Degrades if held hot for long; limit regrind | Stable; tolerates repeated processing and regrind |
| Odour and purity | Higher odour risk | Low odour; used in medical and food-contact compounds |
| Main uses | Shoe soles (TPR), asphalt and roofing membranes, adhesives, polystyrene modification | Soft-touch overmoulding, automotive interiors, wire and cable, medical tubing, PP modification, gels |
| Relative price | Lower | Higher |
Values are typical ranges for compounds, not specifications; molecular weight, styrene content and oil level move every property. Ask for the TDS of the exact grade before you lock a formula.
When SBS is the better choice
- Indoor or short-life products such as footwear, toys, grips and household goods, where UV exposure is low and price matters most.
- Shoe soles and TPR compounds. SBS blended with oil, polystyrene and fillers gives the rebound and grip that footwear needs. Oil-extended SBS-OE grades shorten mixing and make soft compounds easier to process.
- Asphalt and roofing. SBS is the standard polymer modifier for paving bitumen and modified-bitumen roofing membranes.
- Hot-melt and pressure-sensitive adhesives that need high tack at a low cost.
- Low processing temperatures below about 200 °C, where SBS flows easily and saves energy.
When SEBS is the better choice
- Outdoor and sun-exposed parts such as seals, tool and garden-product grips and automotive exterior trim, where SBS would crack or fade.
- Automotive interiors such as soft-touch skins, mats and handles, where low odour, low fogging and heat ageing are specified.
- Soft-touch overmoulding on PP. SEBS compounds bond well to polypropylene in two-shot moulding.
- Medical and personal-care parts such as tubing, seals and stoppers, where purity and sterilization resistance matter.
- Wire and cable jackets and flexible cords that must pass heat-ageing tests.
- Polyolefin modification. Small additions of SEBS raise the impact strength and low-temperature toughness of PP and PE. For most PP compounds POE is the more common modifier; see POE vs EPDM.
SEBS vs SBS by application
A quick way to choose: find the product closest to yours. Where two options are listed, the first is the usual starting point.
| Application | Usual choice | Why |
|---|---|---|
| Shoe soles and TPR compounds | SBS | Rebound and grip at the lowest cost |
| Asphalt paving and roofing membranes | SBS | The standard bitumen modifier |
| Hot-melt and pressure-sensitive adhesives | SBS; SEBS where colour and heat stability matter | High tack at low cost |
| Toys, household grips and other indoor goods | SBS | Little UV exposure; price matters most |
| Soft-touch overmoulding on PP | SEBS | Bonds to PP in two-shot moulding |
| Automotive interior skins, mats and handles | SEBS | Low odour, low fogging, heat ageing |
| Outdoor seals and garden-tool grips | SEBS | UV and ozone resistance |
| Medical tubing, seals and stoppers | SEBS | Purity, low odour, sterilization resistance |
| Wire and cable jackets | SEBS | Passes heat-ageing tests |
| PP and PE impact modification | SEBS, or POE for most PP compounds | Saturated rubber that suits polyolefins |
Choosing an SEBS or SBS grade: styrene content and structure
Once the family is chosen, three grade properties decide how the compound behaves:
- Styrene content. Lower styrene gives a softer, more elastic polymer; higher styrene gives a harder grade with higher tensile strength. Most SEBS and SBS grades sit around 30–33% styrene.
- Linear or radial. Linear grades flow more easily and suit compounding and footwear; radial (star) grades have higher melt strength and are preferred for asphalt modification.
- Molecular weight. Higher molecular weight takes more oil and keeps better compression set, but needs more work to process.
Examples from our range: LCY Globalprene SEBS 9557D and 9645D are 13% styrene grades for film, adhesives and PP toughening, while 7550, 9550 and 9551 are 30–33% styrene grades for TPE compounds, footwear and adhesives. On the SBS side, LCY Globalprene SBS 3411 is a radial grade for asphalt, 3522 and 3527 are soft low-styrene linear grades for shoe soles, 3501 is a general linear grade, and 3546 is a hard, high-styrene grade. Ask us for the TDS of any grade.
Formulation tips for SEBS and SBS compounds
Neither polymer is usually processed neat. A typical TPE compound balances four ingredients: the block copolymer for elasticity, oil for softness, a thermoplastic (PP for SEBS, polystyrene for SBS) for hardness and processing, and a mineral filler for cost.
- Oil: paraffinic white oil is the usual partner for SEBS because it swells the ethylene-butylene mid-block without softening the polystyrene domains. SBS compounds often run on naphthenic or paraffinic process oil.
- Stabilizers: SBS needs a primary antioxidant plus a phosphite, and HALS if any light exposure is expected. SEBS needs far less, but a basic antioxidant package still protects it during compounding.
- Processing aids: a small dose of EBS wax improves mould release and filler dispersion.
- Blends with engineering plastics: maleic-anhydride-grafted SEBS is widely used to toughen polyamide; for MAH-grafted options see our compatibilizer range, and our guide to compatibilizer vs toughening agent.
Price per kilogram vs cost per part
SBS usually costs noticeably less per kilogram than SEBS because it skips the hydrogenation step. The SEBS vs SBS comparison changes when the whole formula is costed: SEBS accepts more oil and filler, needs a lighter stabilizer package and survives regrind and outdoor ageing, so the cost per part, and the cost of a warranty claim, can favour SEBS in long-life products. For short-life indoor goods, SBS remains the economical workhorse. Send us your target hardness, service conditions and annual volume and we will price both routes.
Frequently asked questions
Can I replace SEBS with SBS in an existing formula?
Only if the part never sees UV light, heat ageing or strict odour limits. Expect changes in hardness, compression set and long-term colour, and re-qualify the compound before switching. The reverse swap, from SBS to SEBS, usually needs more oil and a higher melt temperature.
Is SEBS stronger than SBS?
Not necessarily. Neat SBS has high strength and rebound at room temperature, while SEBS keeps its properties better after heat and UV ageing. In compounds, molecular weight, styrene content and oil level matter more than the polymer family.
Do SEBS and SBS need vulcanization?
No. Both are thermoplastic: the polystyrene domains soften on heating and re-form on cooling, so parts can be injection moulded and scrap can be reground. Dynamically vulcanized TPV is a different family, chosen when higher heat and oil resistance are required.
Which is better for asphalt modification?
SBS. Linear and radial SBS grades are the standard modifiers for paving bitumen and roofing membranes; SEBS appears only in a few specialty formulas because of its higher cost.
What do SEBS and SBS stand for?
SBS is styrene-butadiene-styrene: two polystyrene end blocks joined by a polybutadiene mid-block. SEBS is styrene-ethylene-butylene-styrene: the same structure after the butadiene block has been hydrogenated into a saturated ethylene-butylene block.
Is SEBS the same as TPE?
No. TPE is the whole class of thermoplastic elastomers. SEBS and SBS are two members of it, the styrenic block copolymers, and are often the base of TPE compounds. Other TPE families include TPV, TPU, TPEE and TPO.
Get an SEBS or SBS recommendation
Still weighing SEBS vs SBS? Tell us the product, target hardness, service conditions (sunlight, heat, skin contact) and annual volume. We will suggest a grade and a starting formula, email you the TDS and arrange samples. Contact our technical team or write to info@sychemtech.com.
Related products: our SEBS & SBS thermoplastic elastomers, including hydrogenated SEBS grades, SBS grades and oil-extended SBS-OE.
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