CAS Registry Number: 2652-13-3
Molecular Formula: C20H60O8Si9
Molecular Weight: 681.46
Percent Composition: C 35.25%, H 8.87%, O 18.78%, Si 37.09%
Literature References: Prepd by the reaction of hexamethyldisiloxane with octamethylcyclotetrasiloxane and sulfuric acid; by varying the proportions of these reactants, other methylpolysiloxanes of a desired average molecular weight may be prepd: Patnode, Wilcock, J. Am. Chem. Soc. 68, 362 (1946).
Properties: Liquid. bp4.9 173°. d 0.918. nD20 1.3980. Stable. Inert to most chemical reagents and rubber. Maintains about the same viscosity over a wide temp range. Sol in benzene and the lighter hydrocarbons; slightly sol in alc and the heavy hydrocarbons.
Boiling point: bp4.9 173°
Index of refraction: nD20 1.3980
Density: d 0.918
Use: As a basis for silicone oils or fluids designed to withstand extremes of temp; as a foam suppressant in petr lubricating oil.