Polymer product for the selective absorption of dissolved ions
OwnerNorman B. Rainerinventor
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Abstract
A water-swellable polymer product which may be physically bound to an open celled cellulosic sponge is produced by thermally induced amide-forming insolubilization of polyethyleneimine (PEI). The polymer product has high affinity for the absorption of transition metal ions. A cellulosic sponge containing a high add-on of the polymer product is permeable to water and substantially unaffected by water-borne suspended matter.
Claims15
A water insoluble polymer product produced by the thermally induced amide-forming interaction between polyethyleneimine (PEI) having repeating ethyleneamine units, and nitrilotriacetic acid (NTA) having three carboxyl groups, the relative amounts of said PEI and NTA being such that the carboxyl groups of the NTA are converted to amide bonds by interaction with said PEI yet leave an excess of unreacted ethyleneamine units, said polymer product having a propensity to absorb between 100% and 250% of water to produce a water-swollen form, having high affinity for transition metal ions in aqueous solutions in the pH range of 2.5 to 6.5, and having relatively low affinity for ions selected from the group consisting of aluminum, calcium, and magnesium.
A porous product comprised of an open celled cellulosic sponge having physically bound thereto insolubilized polyethyleneimine (PEI) polymer in an amount representing an add-on weight between 20% and 110% of the weight of the cellulose, the air permeability of said sponge being reduced no greater than 75% by virtue of the presence of said polymer, said product having the propensity to absorb more than 2% by weight of transition metal ions.
Dependencies are inferred from the claim text.