Method for making anion exchange and chelant resins including aliphatic amino functional groups
View Patent ↗A method for making an anion exchange or chelant resin comprising a vinyl aromatic polymer including a repeating unit comprising an aromatic ring substituted with an aliphatic amino group, wherein the method comprises the step of reacting a vinyl aromatic polymer with a nitro compound comprising from 1 to 12 carbon atoms with the proviso that the α carbon includes at least one hydrogen.
1. A method for making an anion exchange or chelant resin comprising the steps of:
i) reacting a vinyl aromatic polymer with a nitro compound in the presence of a metal reagent to form a polymer having a repeating unit comprising an aromatic ring substituted with a nitro group, wherein the nitro compound comprises from 1 to 12 carbon atoms with the proviso that the α carbon includes at least one hydrogen, and
ii) reducing the nitro group to form an aliphatic amino group.
2. The method of claim 1 wherein the nitro compound is a nitroalkane.
3. The method of claim 1 wherein the nitro compound is selected from at least one of: nitromethane, nitroethane, 1-nitropropane and 2-nitropropane.
4. The method of claim 1 wherein the reaction between the vinyl aromatic polymer and nitro compound is conducted in the presence of a metal reagent having a reduction potential of from 1.0 to 2.5 V.
5. The method of claim 1 wherein the reaction between the vinyl aromatic polymer and nitro compound is conducted in the presence of a metal reagent selected from at least one of: Mn +3 and Ce +4 .
6. The method of claim 1 wherein the metal reagent is electrochemically regenerated by anodic oxidation.
7. The method of claim 1 where the vinyl aromatic polymer comprises a polymer derived from a reaction mixture comprising styrene and divinylbenzene.