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Description and features

SilQon TMDSO ( tetramethyldisiloxane ), is a colorless clear liquid which has C4H14OSi2 as chemical formula. It is a is a hydrogen terminated siloxane dimer which hydride groups provide a reactive site. This allows reactions with a variety of substances which  contain vinyl groups or with hydroxyl functional polysiloxanes in combination with heat or metal catalysts.

Tetramethyldisiloxane is also known as 1,1,3,3-Tetramethyl-1,3-dihydrodisiloxane.


Europe: SilQon TMDSO is ➔ on stock in our local warehouse . Our lead time is about one week if delivered in 150 Kg plastic drums.

United States, Canada, South America, South Africa and other markets can also be served, please contact our sales department for more details.

This product (CAS: 3277-26-7) has been registered (FULL substance) under REACH (EC) 1907/2006.

Product Identification

CAS number 3277-26-7
EC number 221-906-1
HS code 2931 90 00
EC name 1,1,3,3-tetramethyldisiloxane
IUPAC name [(dimethylsilyl)oxy]dimethylsilane


Appearance Transparant liquid
Assay ≥ 99.00 %
Cl content ≤ 30 ppm


Tetramethyldisiloxane is a siloxane that is used as a monomer in the production of silicone polymers or silicone resins. Besides it finds its application as a chemical intermediate in the production of other organosilicon substances. Further it is used as water proofing agent for textiles, paper and leather.


Available packaging: 150 KG plastic drums.
Special packaging is available on request.


Store tetramethyldisiloxane in a cool, dry and well-ventilated area and in line with legal requirements.


A Material Safety Data Sheets (MSDS) is available for SilQon TMDSO and all other products supplied by Vesta Chemicals BV.

An MSDS describes the hazards of a product and explains how a product can be safely handled, used and stored. Besides it provides important regulatory and emergency response information for the purchased product.

Molecular and structural information

Molecular formula C4H14OSi2
Molecular weight 134.33 g/mol
Smiles notation C[Si-](C)[O+]=[Si](C)C
Structural formula Chemical name: Tetramethyldisiloxane CAS number: 3277-26-7

Physicochemical information

Boiling point70.3 ºC @ 1013 hPa
Bulk density 0.87 g/cm3 @ 20 ºC
Flash point -20 ºC @ 1.013 hPa
Log Pow 4.50
Solubility in water 13 mg/l @ 20 ºC
Vapor pressure 15000 Pa @ 20 ºC

Tetramethyldisiloxane | TMDSO | CAS: 3277-26-7 | Disclaimer. This information is supplied solely for informational purposes and Vesta Chemicals bv makes no guarantees or warranties, either expressed or implied, with respect to the accuracy and use of this data. All product warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.