METHOD FOR OBTAINING BIOPOLYMER FILMS Russian patent published in 2022 - IPC C08J5/18 C08B15/10 C08B3/12 C08J3/75 A61K8/73 A61L15/28 

FIELD: chemical industry.

SUBSTANCE: present invention relates to a method for producing biopolymer films involving the preparation of a reaction mixture in the form of an aqueous solution of a water-soluble polysaccharide or its derivative, carboxyalkyl polysaccharide and/or hydroxyalkyl polysaccharide, represented by a water-soluble cellulose derivative selected from a group including hydroxyethylcellulose, hydroxypropyl cellulose, hydroxybutylcellulose, methylhydroxyethylcellulose, ethyl hydroxyethylcellulose, methylhydroxypropylcellulose, carboxymethylcellulose or a combination of these compounds, and polycarboxylic acid with two or more carboxylic groups of COOH as a crosslinking agent, mixing the prepared solution to complete homogeneity, removing water from it to obtain a dehydrated composite in the form of a film, which is subjected to heat treatment at a temperature of 40 to 150°C, providing conditions for the formation of crosslinking macromolecules of polysaccharide or its derivative with polycarboxylic acid, characterized in that an aqueous solution containing 1.0-5.0 wt. %, is prepared of the specified water-soluble polysaccharide or its derivative, represented by a water-soluble cellulose derivative selected from the above group, and 0.5-4.0 wt. %, polycarboxylic acid with two, three or four carboxyl groups of COOH, while before dehydration of the reaction mixture, it is kept in an ultrasonic bath at room temperature for 30-40 minutes, and then in a vacuum cabinet at a pressure of 1.5-10.0 mm Hg and a temperature of 25-40°C for 30-50 minutes, and for crosslinking, heat treatment of the dehydrated composite is carried out for a time from 10 minutes to 7 days.

EFFECT: present invention provides an increase in the stability of the obtained biopolymer films in water and aqueous solutions and an increase in their mechanical strength by increasing the number of cross-links between the macromolecules of the biopolymer, which ensures limited swelling of the films without exceeding the stability threshold and reversible water absorption, while improving their consumer qualities by ensuring optical transparency and eliminating defects in the formed biopolymer films.

3 cl, 2 dwg, 9 ex