FIELD: chemistry.
SUBSTANCE: invention relates to polyethoxysiloxanes and use thereof. Disclosed is a polyethoxysiloxane (PES) based substance which is obtained through (a) a first reaction for hydrolysis-condensatio of tetraethoxysilane of formula SiX4 (I), wherein X is an ethoxy group, which is catalysed by an acid at initial pH from 0 to ≤7 in the presence of ethanol or a mixture of ethanol and water as a solvent for 1-24 hours at temperature of 0-78°C, the initial pH being established using diluted nitric acid or an acid mixture of a physiologically transferred acid and a substrate made from nitroxide synthase, (b) a second reaction of hydrolysis-condensation of the substance obtained at step (a), and simultaneous removal of the solvent by gradual evaporation in a closed, gas-impermeable container at pressure of 100-1013 mbar and temperature of 50-78°C, until sharp increase in viscosity (at shear velocity of 10 s-1 at 4°C) to 0.5-2 Pa·s, until achieving constant weight and until formation of cyclotetrasiloxane of general formula ((SiO(OH)0.75(OEt)1.25×1/64 H2O)4 and molar mass 4 x about 114 g = about 456 g, (c) cooling the PES in a closed container for a period ranging from a few minutes to a few hours and (d) converting the PES obtained at step (c) into a PES substance through a third hydrolysis-condensation reaction. Use of the obtained substance is also disclosed.
EFFECT: obtained substance is non-toxic and its sol solution is suitable for spinning.
12 cl, 1 ex
Authors
Dates
2013-02-27—Published
2008-06-03—Filed