GB986999A - A process for the production of sodium carboxymethylcellulose from jute and oil-in-water emulsions prepared therefrom - Google Patents

Abstract

Sodium carboxymethyl cellulose is made by steeping pure jute cellulose in a 30-70% caustic soda solution for 1-2 hours at 20-25 DEG C., with a cellulose/alkali solution ratio of from 1 : 4 to 1 : 5 (weight/volume) pressing out excess of alkali from the mass, and mixing the resulting sodium cellulose with chloroacetic acid for 4 to 6 hours at 35-45 DEG C., whereby sodium carboxymethyl cellulose having a degree of substitution of 0.6 to 1.1 is obtained. Preferably, the excess of alkali is pressed out to a weight of 4-5 times the original weight of cellulose. Solid chloracetic acid, or a 70-80% solution thereof, may be used, but the sodium cellulose must not be allowed to dry during the reaction with chloracetic acid. The product may be freed from glycollic acid impurities by washing with acetone or hot 80% by weight ethyl alcohol. The degree of substitution of the product may be varied by adjustment of the concentration of the caustic soda solution. For the method of preparing the jute cellulose (see Division D2); for the use of the products as emulsion stabilizers (see Division B1).ALSO:Oil-in-water emulsions contain as emulsifying agent a sodium carboxymethyl cellulose having a degree of substitution of 0,6 to 1,1. In examples: (i) an emulsion of olive oil and water in a ratio of 1 : 2 by volume is stabilized by the addition of said agent in a concentration of 2,5% (w/v) of the aqueous phase. The emulsion is stable for 40 days and shows no creaming; (ii) castor oil and water emulsions in ratios of 1 : 1 and 1,5 : 1 by volume are stabilized by the addition of said agent in a concentration of 2% of the aqueous phase. The emulsions are stable for 30 days and show no creaming. For the preparation of the sodium carboxymethyl cellulose from jute cellulose, see Division C3.ALSO:Pure jute cellulose is prepared either by chlorinating powdered jute, removing the resulting chloro derivatives of lignin by boiling with sodium sulphite, and repeating this treatment until the jute powders becomes white, or alternatively by boiling powdered jute in about 1% caustic soda solution, placing the jute after washing with water under a slow stream of chlorine till the jute becomes golden yellow, boiling the chlorinated jute with about 2% sodium sulphite solution (containing 0.2% NaoH) and washing the resulting product with hot water whereby pure, white jute cellulose is obtained. Powdered jute for either process may be made by cutting jute fibres or jute cuttings into small pieces and milling. For the use of the product in the preparation of sodium carboxymethyl cellulose see Division C3.