Silane Coupling Agent Si69 (Bis-TESPD)
CAS Number: 40372-72-3
Silane Coupling Agent Si69 (bis[3-(triethoxysilylpropyl)]-tetrasulfide, Bis-TESPD) is the industry benchmark silane for silica-filled green tire tread compounds. It reacts with silanol groups on precipitated silica during mixing to reduce silica-silica interactions and covalently bonds the silica surface to the rubber polymer during vulcanization. Si69 significantly reduces rolling resistance and improves wet traction in silica-based tire treads while maintaining acceptable processing viscosity.
Technical Specifications
| appearance | Brown to dark brown liquid |
| purity (%) | ≥95.0 |
| moisture (%) | ≤0.10 |
| sulfur content (%) | 22.0–23.5 |
| refractive index (20°C) | 1.466–1.472 |
| specific gravity (20°C) | 1.079–1.089 |
Applications
- Silica-filled green tire tread compounds
- High-performance and fuel-efficient passenger tire treads
- Winter tire tread formulations
- Silica-reinforced NR/SBR/BR blends
- Low rolling resistance commercial vehicle tire treads
Key Features
- Industry-standard silane for silica-rubber coupling in green tires
- Reduces silica networking for lower compound viscosity and hysteresis
- Covalent silica-polymer bond formed during vulcanization
- Compatible with DPG activator for optimized silanization
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CAS Number
40372-72-3
Category
Rubber / Tire ChemicalsAvailability
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