Polysiloxanes di-Me hydroxy-terminated

Polysiloxanes di-Me hydroxy-terminated (CAS 70131-67-8), also known as hydroxy-terminated polydimethylsiloxane or PDMS-OH, is a reactive silicone polymer used as a building block and functional additive in silicone-based manufacturing.

Where is Polysiloxanes di-Me hydroxy-terminated used?

• Sealants and elastomers: base polymer for room-temperature vulcanizing (RTV) silicone systems, where hydroxyl end groups react with crosslinkers to form flexible networks
• Coatings and release liners: controls surface energy and improves substrate wetting
• Rubber compounding and tire manufacturing: processing aid and reactive modifier that adjusts flow behavior and mechanical properties
• Textile and paper treatment: imparts softness, water repellency and controlled slip
• Its terminal hydroxyl groups enable direct participation in crosslinking and condensation cure reactions.
• In construction silicone and industrial sealing, viscosity and mechanical properties are adjusted by selecting the molecular weight.
• Used in heat-resistant tiles.

Formulation notes

• Terminal silanol groups make polydimethylsiloxane susceptible to condensation under mild acid and base conditions.

Typical specification

• The 5,000 cSt grade has a molecular weight of 49,000 g/mol, 0.07 wt% OH, and 0.039-0.043 OH eq/kg.
• Soluble in chloroform, diethyl ether, toluene and other organic solvents; insoluble in water and ethanol.

Frequently asked questions about Polysiloxanes di-Me hydroxy-terminated

How does polysiloxanes di-Me hydroxy-terminated function in plastic and polymer systems?

In plastic and polymer systems it functions as a crosslinker or chain extender for functional silicone networks.

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