Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

(1,1,3,3-Tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl dimethacrylate is a liquid at standard temperature and pressure, with a measured melting point of <-80°C. The substance was observed to undergo thermal decomposition from >200°C at 1013 hPa. It has a predicted density of 0.90 g/cm3 at 20°C and a predicted vapour pressure of 0.005 Pa at 25°C.

The substance is not classified for flammability according to Regulation (EC) No. 1272/2008 on the basis of a flash point of 137°C and a decomposition temperature of >200°C at 1013 hPa. It has a measured auto-ignition temperature of 288°C at 1013 hPa, and is not explosive and not oxidising on the basis of structural examination.

In contact with water, (1,1,3,3-tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl dimethacrylate reacts slowly (half-life of 1.1 hours at pH 4, 63 hours at pH 7, 0.8 hours at pH 9 and 20-25°C) to produce 3-[hydroxy(dimethyl)silyl]propyl methacrylate according to the following equation:

C18H34O5Si2+ H2O → 2C9H18O3Si


(1,1,3,3-Tetramethyldisiloxane-1,3-diyl)dipropane-1,3-diyl dimethacrylate has a predicted log Kow value of 8.1 at 20°C and predicted water solubility value of 1.5E-03 mg/l at 20°C.

The saturation concentration in water of the silanol hydrolysis product, 3-[hydroxy(dimethyl)silyl]propyl methacrylate is limited by condensation reactions to approximately 30 mg/l with a predicted log Kow value of 2.6. It is not surface active and has a predicted vapour pressure of 4.8E-02 Pa at 25°C.


Additional information