Polymer-supported chelating agent

Patent metadata

Field	Value
Publication number	US-2018339286-A1
Application number	US-201815980680-A
Country	US
Kind code	A1
Filing date	May 15, 2018
Priority date	May 25, 2017
Publication date	Nov 29, 2018
Grant date	—

Abstract

The polymer-supported chelating agent is polyisobutylene having a thiol-thioether terminal group. The polymer-supported chelating agent is made by reaction of the terminal carbon double bond of polyisobutylene with 1,2-ethanedithiol in a one-step click reaction, resulting in PIB functionalized with a thiol-thioether sequestering group. In use, the polymer-supported chelating agent is added to a biphasic solvent system containing a transition metal in solution for removal of the transition metal by liquid/liquid extraction. The transition metal is chelated or sequestered by the chelating agent and removed in a nonpolar organic phase, such as heptane.

First claim

I claim:

1 . A polymer-supported chelating agent, comprising polyisobutylene having a terminal group, the terminal group being a chelating agent.

2 . The polymer-supported chelating agent according to claim 1 , wherein the chelating agent comprises a thiol-thioether.

3 . The polymer-supported chelating agent according to claim 1 , having the formula:

4 . A method of synthesizing the polymer-supported chelating agent according to claim 3 , comprising the steps of:
dissolving alkene-terminated polyisobutylene and 1,2-ethanedithiol in a solvent mixture of ethanol and heptane, the solvent mixture being 1:1 ethanol:heptane volume-to-volume to form a reaction mixture; adding a polymerization initiator to the reaction mixture; and irradiating the reaction mixture with ultraviolet light.

5 . The method of synthesizing the polymer-supported chelating agent according to claim 4 , wherein said polymerization initiator comprises azobisisobutyronitrile (AIBN).

6 . The method of synthesizing the polymer-supported chelating agent according to claim 4 , wherein said polymerization initiator comprises di-tert-butyl peroxide (DTBP).

7 . The method of synthesizing the polymer-supported chelating agent according to claim 4 , wherein said step of irradiating the reaction mixture with ultraviolet light comprises irradiating the reaction mixture with ultraviolet light at a wavelength of 365 nm.

8 . The method of synthesizing the polymer-supported chelating agent according to claim 4 , wherein said step of irradiating the reaction mixture with ultraviolet light at a wavelength of 365 nm is performed at 25° C.

9 . A method of removing a transition metal from a polar solvent using the polymer-supported chelating agent according to claim 3 , comprising the steps of:
dissolving at least a stoichiometric quantity of the polymer-supported chelating agent according to claim 3 in an extraction solvent; mixing the extraction solvent with a polar solvent having the transition metal in solution to selectively extract the transition metal into the extraction solvent by chelation of the transition metal; waiting for the extraction solvent and the polar solvent to separate into a nonpolar phase and a polar phase; and separating the nonpolar phase from the polar phase, the polymer-supported chelating agent having the transition metal chelated thereto being selectively solvated in the nonpolar phase.

10 . The method of removing a transition metal from a polar solvent according to claim 9 , wherein said extraction solvent comprises heptane.

11 . The method of removing a transition metal from a polar solvent according to claim 9 , wherein said extraction solvent comprises dichloromethane.

12 . The method of removing a transition metal from a polar solvent according to claim 9 , wherein said mixing step further comprises heating the mixed extraction and polar solvents at 80° C.

13 . The method of removing a transition metal from a polar solvent according to claim 9 , wherein said at least stoichiometric quantity comprises a six-fold excess of the polymer-supported chelating agent according to claim 3 .

14 . A method of synthesizing a polymer-supported chelating agent, comprising the steps of:
dissolving alkene-terminated polyisobutylene and 1,2-ethanedithiol in a solvent mixture of ethanol and heptane, the solvent mixture being 1:1 ethanol:heptane volume-to-volume to form a reaction mixture; adding a polymerization initiator to the reaction mixture; and irradiating the reaction mixture with ultraviolet light at a wavelength of 365 nm.

15 . The method of synthesizing the polymer-supported chelating agent according to claim 14 , wherein said polymerization initiator comprises azobisisobutyronitrile (AIBN).

16 . A method of recovering a transition metal of a transition metal catalyst from a spent reaction mixture, comprising the steps of:
dissolving a six-fold excess over a stoichiometric quantity of a polymer-supported chelating agent having the formula:

into a nonpolar organic solvent to form an extraction solvent;
adding a polar solvent to the spent reaction mixture containing the transition metal catalyst, the transition metal catalyst being soluble in the polar solvent, in order to form a polar phase;
mixing the extraction solvent with the polar phase having the transition metal in solution to selectively extract the transition metal into the extraction solvent by chelation of the transition metal;
waiting for the extraction solvent and the polar solvent to separate into a nonpolar phase and a polar phase; and
separating the nonpolar phase from the polar phase, the polymer-supported chelating agent having the transition metal chelated thereto being selectively solvated in the nonpolar phase to recover the transition metal of the transition metal catalyst.

17 . The method of recovering a transition metal catalyst according to claim 16 , wherein said nonpolar organic solvent comprises heptane.

Assignees

• Qatar Found Education Science & Community Dev

Inventors

• Bazzi Hassan Said
• Al-Hashimi Mohammed
• Bergbreiter David E
• Chouikhi Dalila

Classifications

• C22B11/048

  from spent catalysts · CPC title

• B01J45/00

  Ion-exchange in which a complex or a chelate is formed; Use of material as complex or chelate forming ion-exchangers; Treatment of material for improving the complex or chelate forming ion-exchange properties (ion-exchange chromatography processes B01D15/36) · CPC title

• C22B7/009

  General processes for recovering metals or metallic compounds from spent catalysts (for recovering specific metals C22B11/00 - C22B61/00) · CPC title

• B01J20/3085

  Chemical treatments not covered by groups B01J20/3007 - B01J20/3078 · CPC title

• C22B3/1616

  Leaching with acyclic or carbocyclic agents of a single type · CPC title