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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

1,1,3,3-Tetramethyl-1,3-divinyldisiloxane (Vi2-L2) is a liquid at ambient temperature and pressure, with a measured melting point of -99.7°C and a predicted boiling point of 130°C. It has a measured density of 0.811 g/cm3at 20±0.02°C, a predicted kinematic viscosity of 0.9 mm2/s at 20°C and measured vapour pressure values of 870 Pa at 20°C and 1700 Pa at 25°C.

Measured flash point values are available for two samples of the registration substance. For the first, which was performed using a closed cup method according to ASTM D 3828-97, the flash point was 21.7°C, which with a boiling point of 130°C, requires classification as a highly flammable liquid (Category 2) in accordance with Regulation (EC) No 1272/2008.

For the second sample, performed in accordance with ISO 13736:1997 and EU Test Method A.9 closed cup method, gave a flash point of 24°C, resulting in classification as a flammable liquid (Category 3) in accordance with Regulation (EC) No 1272/2008.

The substance has a measured self-ignition temperature of 271°C, and it is not explosive and not oxidising on the basis of structural examination.

The substance has a measured log Kowof 5.4 at 20°C and a measured water solubility of 0.207 mg/l at 20°C. It is not surface active based on structural examination.

In contact with water,Vi2-L2 will hydrolyse slowly with measured hydrolysis half-lives of 3.7 hours at pH 5, 5.8 d (139 hours) at pH 7 and 2.6 hours at pH 9 and 25°C as shown in the equation below:

[H2C=CHSi(CH3)2]2O+ H2O    2H2C=CHSi(CH3)2OH