Bis[3-(Triethoxysilyl) propyl]disulfide stands out within the world of organosilane coupling agents thanks to its unique disulfide bridge. Those who work in rubber manufacturing or advanced chemical synthesis know this name, often abbreviated as TESPD or SI69. This compound brings together two triethoxysilylpropyl groups joined by a disulfide bond, designed for those seeking to boost performance, especially where rubber and inorganic fillers come together. With a molecular formula of C18H42O6S2Si2 and a molecular weight around 538.84 g/mol, its structure packs both silicon and sulfur, opening up roads between organic polymers and inorganic surfaces in countless applications.
Open a drum of Bis[3-(Triethoxysilyl) propyl]disulfide and you’ll spot a pale yellow liquid, sometimes clear, carrying a faint odor. Factory floors and research labs both keep this liquid handy, noticing its consistency that falls between syrup and oil at room temperature. If temperature drops below about 10°C, small crystals or flakes might appear, but gentle warming brings it right back. Density ranges from 1.08 to 1.13 g/cm³ at 25°C, and the boiling point sits high—well over 300°C—so it doesn’t vanish during processing. With a flashpoint above 120°C, shipping and handling worries don’t spike, as risk of dangerous vapor release is lower than many volatile organosilanes.
At the heart of Bis[3-(Triethoxysilyl) propyl]disulfide’s utility is the long, flexible chain linking the two triethoxysilylpropyl units through a disulfide bond. All six ethoxy groups react with water to generate silanols, allowing the molecule to bond strongly with glass, silica, or mineral surfaces, forming robust siloxane networks after hydrolysis and condensation. This dual reactivity means the molecule can link rubber to silica, boosting tire grip, reducing rolling resistance, and, by extension, improving fuel efficiency. The disulfide functionality can take part in vulcanization reactions, tying itself deeper into rubber structures compared to monosulfide analogues.
Industry demands reliability from key materials. For those sourcing Bis[3-(Triethoxysilyl) propyl]disulfide, purity figures often reach 97% or higher, with trace byproducts tightly controlled. Product usually ships as a liquid in steel drums or IBC totes, but custom orders might see flakes or low-melting solids if logistics require. Some manufacturers push raw material control further, monitoring for metal content below one part per million and guaranteeing consistent reactivity for process repeatability in tire factories or sealant plants. Water content sits below 0.5%, and color standards (APHA) stay below 100. The HS Code for trade sits at 2931.90.9000, streamlining customs clearance for chemical companies and downstream users worldwide.
Each Bis[3-(Triethoxysilyl) propyl]disulfide molecule covers considerable ground thanks to its 18 carbons, 6 oxygens, 2 sulfurs, and 2 silicons. Keeping the density just over 1 g/cm³ means it stores well, doesn’t require special pumping equipment, and pours easily without aggressive agitation. Some warehouses store it as pellets or “pearls” if spillage control or automated dosing come into play, while most users stick to the liquid for process simplicity. Whether weighed by the liter or by calculated mole, the material offers flexibility for formulation: a few liters suffice for lab-scale runs, while tons serve automotive or construction industries each year.
Bis[3-(Triethoxysilyl) propyl]disulfide, while safer than many lower-boiling organosilanes, still calls for respect. Direct skin contact may bring irritation, and inhalation in aerosol-heavy environments can bother those without proper protective gear. Spills need quick cleanup with absorbents, and gloves, goggles, and chemical aprons keep exposures low on busy production lines. SDS sheets warn of environmental risks if discharged unchecked, since silane derivatives slowly hydrolyze but sulfur content threatens aquatic life. Special attention falls on ventilation, keeping indoor vapor concentration well below tolerable exposure limits. Fire isn’t a major concern due to the high flashpoint, yet regular staff training makes a big difference in long-running operations. Safe storage calls for sealed drums, cool and dry spaces, and separation from acids and oxidizers to avoid unwanted reactions, and proper labeling meets regulations for hazardous chemicals and raw materials across global supply chains.
This compound’s true reach runs deep in raw material supply chains. Its dual-mode bonding eases the eternal headache of balancing cost and tire performance for automotive engineers. The ability to fine-tune rubber compounding and tack up strong bonds to glass or mineral fillers grants leverage to those pushing for lighter, more fuel-efficient vehicles. From an operational standpoint, availability as a liquid minimizes waste when batching, and clear HS Code classification keep global shipments on schedule. Sourcing teams vet quality at each step, making sure raw materials including ethanol, silanes, or sulfur meet purity thresholds. With increasing regulatory pinches on harmful chemicals, Bis[3-(Triethoxysilyl) propyl]disulfide’s manageable hazard profile helps manufacturers favor it over older, riskier alternatives.
As sustainability steers industry, questions about Bis[3-(Triethoxysilyl) propyl]disulfide’s long-term future pop up on conference tables and in procurement chats. Full-life-cycle safety data, persistent organic pollutant monitoring, and responsible waste stream treatment all rank higher than they did a decade ago. While the compound’s volatility remains manageable, the drive to reduce emissions and control worker exposures keeps R&D teams searching for even cleaner production routes, like greener ethanol supplies or safer catalyst alternatives. Responsible companies monitor for harmful degradation byproducts, recycle process wash streams, and push partners upstream and downstream to climb higher on safety and transparency. Ongoing collaboration between manufacturers and regulatory agencies shapes not only safer workplaces but also supply chains resilient to disruption and future chemical bans. Chemical users, from tire engineers to lab chemists, benefit from these trends with higher product confidence and a wider set of processing options while environmental standards step up year after year.
