Superabsorbent polymer material comprising non-crosslinked polyacrylic acid polymer
AssigneeThe Procter & Gamble Company
InventorsArsen Arsenov SIMONYAN, Natasa DIJAKOV, Dimitris Ioannis COLLIAS, Yiping SUN
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Abstract
Superabsorbent polymer material comprising cross-linked polyacrylic acid and salts thereof. The superabsorbent polymer material further comprising at least 3.0 weight-%, based on the total weight of the superabsorbent polymer material, of soluble polyacrylic acid polymers. A method for making such superabsorbent polymer materials is also disclosed.
Claims20
A superabsorbent polymer material comprising cross-linked polyacrylic acid and salts thereof, the superabsorbent polymer material further comprising at least 3.0 weight-%, based on the total weight of the superabsorbent polymer material, of soluble polyacrylic acid polymers, wherein the cross-linked polyacrylic acid and salts thereof have an average distance Rx1 between neighboring crosslinks, as calculated for the superabsorbent polymer material loaded with 20 g of saline with 0.9% w NaCl per gram of dry superabsorbent polymer material, and wherein the at least 3 about weight-% of soluble polyacrylic acid polymers have an average diameter of gyration 2*Rg, and
- wherein the ratio of 2*Rg to Rxl is at least 1.1.
A method of making superabsorbent polymer material comprising the steps of:
- a) providing an aqueous solution of polymerizable acrylic acid monomers and/or polymerizable acrylic acid oligomers, optionally neutralizing at least some of the polymerizable acrylic acid monomers and/or polymerizable acrylic acid oligomers;
- b) optionally providing one or more ethylenically unsatured co-monomers, optionally neutralizing at least some of the ethylenically unsatured co-monomer of step b);
- c) providing one or more crosslinker(s);
- d) providing one or more initiator(s);
- e) providing at least about 3 weight-% of soluble polyacrylic acid polymers based on the total weight of the soluble polyacrylic acid polymers provided in step e) and the monomers, oligomers, co-monomers, crosslinkers and initiators provided in steps a) to d);
- f) mixing the aqueous solution of monomers, oligomers, co-monomers, crosslinkers and initiators and soluble polyacrylic acid polymers provided in steps a) to e);
- and
- g) polymerizing the mixture obtained in step f) to obtain a superabsorbent polymer material.
Dependencies are inferred from the claim text.