Isoprene-styrene copolymer

Isoprene-styrene copolymer (CAS 25038-32-8), commercially recognized as Styrene Isoprene Styrene (SIS), is a thermoplastic elastomer block copolymer.

Where is Isoprene-styrene copolymer used?

• Hot-melt pressure-sensitive adhesives: primary base polymer
• Labels, tapes and hygiene product construction: natural tack and cohesive strength determine bond performance
• Roofing and waterproofing membranes: modifies bitumen to improve low-temperature flexibility
• Construction: resistance to thermal creep
• Molded and extruded rubber profiles: adjusts hardness and elastic recovery
• Household and industrial contact adhesives: open-time control and peel strength
• It delivers elastic recovery and melt processability without requiring vulcanization.
• Processable by thermoplastic methods such as extrusion, injection molding and film blowing.
• Used as a modifier for polymers, thermosets and general rubber compounds.
• Used in the production of films, laminates and elastomeric fibers for footwear, sports equipment, flexible packaging and protective equipment.
• Used in vibration damping, noise reduction and cushioning materials for automotive parts, protective packaging and industrial equipment.
• Used in medical, personal care and hygiene applications such as transdermal patches, wound dressings, flexible bandages and wearable medical devices.

Good to know: Styrene content and diblock ratio differentiate commercial grades; food-contact compliance varies by grade and should be confirmed against applicable regulations.

Typical specification

• Styrene content typically 14–22%.
• Stypol 3000 is a grade with 30% styrene content, 0% diblock content, melt flow rate 11.0 g/10min, Shore A hardness 62, tensile strength 22 MPa, elongation at break 950% and viscosity 300 mPa·s.

Regulatory status

• Not classified as dangerous goods for transport.
• Not a hazardous substance under EU REACH, with a polymer exemption applying, but component monomers are registered.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.