Preparation of oligomethylsiloxanes

Oligomethylsiloxanes are a mixture of liquid products, mainly of the linear structure  

They differ in viscosity, which has a wide range (from 0.65 to 1 106 mm2/s) and depends on the degree of polymerisation n. 

These liquids can be obtained by the hydrolytic cocondensation of mono- and dichlorine-containing methylsilanes 

The process can be catalysed wih mineral acids, metal sulphates, activated silica-alumina clays or zeolites. 

Raw stock dimethyldichlorosilane [not less than 58% (weight) of chlorine, the density of 1.06-1.07 g/cm3] trimethylchlorosilane [32.1-33.2% (weight) of chlorine, the density of 0.856-0.859 g/cm3] kil clay treated with sulfuric or hydrochloric acid. 

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