SBS is a type of SBC, specifically containing butadiene as the elastomeric mid-block. SBC is a broader class that includes various styrenic block copolymers, including SBS, SEBS, and SIS. So, SBS is one type of SBC, just like how apples are a type of fruit!
- SBS Polymer (Styrene-Butadiene-Styrene)
- SBS is a specific type of styrenic block copolymer (SBC).
- It consists of three blocks: polystyrene (S) at both ends and polybutadiene (B) in the middle.
- Properties:
- High elasticity and flexibility (due to the rubbery butadiene block).
- Good impact resistance and toughness.
- Thermoplastic behavior—softens when heated and hardens when cooled.
- Used in applications like adhesives, asphalt modification, footwear, and soft-touch materials.
- SBC Polymer (Styrenic Block Copolymer)
- SBC is a broader category that includes SBS, but also other styrenic block copolymers such as:
- SIS (Styrene-Isoprene-Styrene) – Uses isoprene instead of butadiene.
- SEBS (Styrene-Ethylene-Butylene-Styrene) – A hydrogenated version of SBS.
- SEPS (Styrene-Ethylene-Propylene-Styrene) – A hydrogenated version of SIS.
- Properties:
- Varies depending on the specific polymer.
- SEBS and SEPS have better UV and oxidation resistance compared to SBS.
- Different SBCs are chosen based on required properties like softness, durability, or weather resistance.
Key Difference
- SBS is a type of SBC, but not all SBCs are SBS.
- SBC refers to a broader family, while SBS is a specific type with defined styrene and butadiene blocks.
- SEBS and SEPS are often used when higher heat and oxidation resistance are needed, while SBS is preferred for cost-effective elastomeric applications.