METHOD OF PRODUCING LINEAR POLYMETHYLPHENYLSILOXANE WITH TERMINAL HYDROXYL GROUPS VIA POLYCONDENSATION OF METHYLPHENYLDIALKOXYSILANE IN ACTIVE MEDIUM Russian patent published in 2012 - IPC C08G77/06 

FIELD: chemistry.

SUBSTANCE: disclosed is a method of producing linear oligomethylphenylsiloxanes with terminal hydroxyl groups via polycondensation of methylphenyldialkoxysilane selected from methylphenyldialkoxysilanes of general formula (I) (CH₃)(C₆H₅)Si(OAlk)₂ (I) where Alk denotes an alkyl group from C₁ to C₄, in an active medium which is an anhydrous carboxylic acid until complete conversion of alkoxy groups. The carboxylic acid used is selected from: formic, acetic, propionic, isobutyric and trimethylacetic acid. Molar ratio of methylphenyldialkoxysilane to carboxylic acid ranges from 1:3 to 1:10. The polycondensation process in the active medium is carried out at temperature ranging from 20°C to boiling point of the reaction mixture. Removal of volatile components is carried out in a vacuum at 20°C.

EFFECT: achieving complete conversion of the starting methylphenyldialkoxysilane and alkoxy groups, low content of cyclic products and environmental friendliness of the process.

6 cl, 2 dwg, 1 tbl, 7 ex