Registration Dossier

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