Superabsorbent polymers from cross-linked polyacrylonitrile emulsions
AssigneeBayer Aktiengesellschaft
InventorsGunter Sackmann, Siegfried Korte, Sergej Schapowalow, Klaus Szablikowski, Wolfgang Koch
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Abstract
Superabsorbent polymers based on partly hydrolysed homopolymers and/or copolymers of acrylonitrile which are cross-linked through the incorporation of polyfunctional monomers, wherein 30 to 80 mol-% of the nitrile groups are converted into carboxylate groups, 20 to 70 mol-% of the nitrile groups are converted into carbonamide groups and 0 mol-% to 20 mol-% of the nitrile groups are unchanged, and the said cross-linked polymers possess a swelling capacity of 700 g/g in water and of up to 60 g/g in physiological saline and a gel strength of from 20 g to 100 g, their preparation and their use.
Claims10
Method for the preparation of superabsorbent polymers, characterised in that fine-particled aqueous emulsions of cross-linked homopolymers and/or copolymers of acrylonitrile are partly hydrolysed by reaction with aqueous solutions of alkali hydroxides, the polymers are precipitated as powders by addition of organic solvents which are miscible with water, are separated out, dried and then optionally heated for a short period.
Dependencies are inferred from the claim text.