Membrane filtration of polymer containing solutions
AssigneeAlbright & Wilson UK Limited
InventorMohsen Zakikhani
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Abstract
In a method for recovering polymers in a substantially pure form from a solution containing the polymers, the solution is first treated with a reactant (e.g. an acid, a sequestrant or a mixture of both) to form the free polymers and salts of the reactant. Second, the solution is treated to remove the salts therefrom and in a final stage the polymer solution is concentrated and the polymers recovered. The second treatment step may consist of membrane-filtration, ion-exchange or electrodialysis.
Claims8
A method of recovering polymers in a substantially pure form from a solution containing said polymers, wherein said method comprises the following steps:
- (a) treating said solution with a reactant so as to form free polymers and one or more salts of said reactant in said solution;
- (b) subjecting said solution (a) to membrane filtration to remove said one or more salts therefrom;
- (c) concentrating said membrane filtered solution (b) and recovering said free polymers therefrom;
- and
- wherein said solution contains at least one polymer selected from the group consisting of
- (i) copolymers of vinylphosphonic acid and acrylic acid;
- (ii) copolymers of vinylphosphonic acid and methacrylic acid;
- (iii) homopolymers of vinylphosphonic acid;
- (iv) oligomers of vinylphosphonic acid;
- (v) terpolymers of vinylphosphonic acid, acrylic acid and vinylsulphonic acid;
- (vi) homopolymers of vinylidene-1, 1-diphosphonic acid (VDPA);
- (vii) copolymers of VDPA with a water-soluble monomer;
- (viii) terpolymers of VDPA and two water-soluble monomers;
- (ix) VDPA-funtionalised polymers;
- and
- (x) polymers containing phosphono-succinic acid.
Dependencies are inferred from the claim text.