CATIONIC POLYMERS OF BIOLOGICAL ORIGIN Russian patent published in 2000 - IPC

FIELD: chemistry of polymers. SUBSTANCE: described are cationic polymers of biological origin with average molecular weight from 800,000 to 1,200,000 Dalton with Bruedfield viscosity measured as 1 wt % of solution in glycolic acid of lower than 5000 mPa with deacetylation degree from 80 to 88% and ash content of less than 0.3 wt prepared by (a) treatment of shells of fresh crustacean with dilute aqueous mineral acid, (b) treatment of the resulting first demineralized intermediate product with 5-25 % by weight with aqueous solution of alkali metal hydroxide, (c) treatment of the resulting second deproteinized intermediate product with dilute aqueous mineral acid, (d) drying, if required, third decalcined intermediate product to residual water content of 5-25 wt % and (e) deacetylation with 50-70 by weight of aqueous solution of alkali hydroxide; in this case stages (a) and (c) are carried out at temperatures from 15 to 25 C and pH value from 12 to 14. Polymers have high molecular weight, are readily soluble and low viscous in organic solutions and also have perfect film-forming properties. EFFECT: improved properties of the cationic polymers. 4 cl, 3 ex, 2 tbl