Chitosan derivative, a method for its preparation and its use as an adsorption agent

Patent metadata

Field	Value
Publication number	US-9187345-B2
Application number	US-201214114777-A
Country	US
Kind code	B2
Filing date	Jun 27, 2012
Priority date	Jun 28, 2011
Publication date	Nov 17, 2015
Grant date	Nov 17, 2015

Abstract

The present invention relates to a cross-linked thiazolidinone chitosan dibenzo crown ether, a method for its preparation as well as its use as adsorbent.

First claim

The invention claimed is:

1. Chitosan derivative having the repeating unit of formula 1

wherein each A is independently selected from

A is vicinally bound to the crown ether,
n equals 1 or 2,
X is selected from CHR 4 , NH, O or S,
Y is selected from CR 4 or N,
L is selected from CR 5 or N,
R 1 , R 2 , R 3 , R 4 and R 5 are independently selected from hydrogen, halogen, C 1 -C 20 -alkyl, C 1 -C 20 -alkoxy, mercapto, alkylthio, alkylamino, arylthio, heteroarylthio, arylamino and heteroarylamino.

2. Method for preparing a chitosan derivative according to claim 1 , comprising the step:
a. reacting a cross-linked chitosan crown ether (7) with an alpha-mercapto carboxylic acid and/or a beta-mercapto carboxylic acid to result in a chitosan derivative (1), according to the following scheme 1:

wherein step (i) takes place in the presence of a zinc chloride and an organic solvent in a temperature range from 50-150° C.

3. Method according to claim 2 , wherein the alpha-mercaptocarboxylic acid is mercaptoacetic acid.

4. Method according to claim 2 , wherein the beta-mercaptocarboxylic acid is beta-mercaptopropionic acid.

5. Method according to claim 2 , wherein the organic solvent is 1,4-dioxane.

6. Method according to claim 2 , wherein step (i) takes place under microwave irradiation.

7. Method according to claim 6 , wherein the power of the microwave irradiation is in a range from 30-300 W.

8. Method according to claim 6 , wherein the irradiation time is in a range from 1-60 min.

9. Method of adsorbing metal ions comprising exposing metal ions to the chitosan derivative according to claim 1 .

10. Method according to claim 9 , wherein the metal ions are heavy metal ions.

11. Method according to claim 9 , wherein the chitosan derivative is recycled after adsorption by removal of the metal ions via acidic treatment.

12. Method according to claim 9 , wherein the metal ions are removed from water.

13. Method according to claim 9 for the separation of mercury ions from other metal ions by selective adsorption.

Assignees

• Al-Sarra Ibrahim Abdallah
• Alanazi Fars Kaed
• Radwan Awwad Abdoh
• Univ King Saud

Inventors

• Al-Sarra Ibrahim Abdallah
• Alanazi Fars Kaed
• Radwan Awwad Abdoh

Classifications

• C02F1/286 Primary

  using natural organic sorbents or derivatives thereof · CPC title

• B01J20/3425

  of sorbents or filter aids comprising organic materials · CPC title

• B01J20/267

  Cross-linked polymers · CPC title

• C02F1/42 Primary

  by ion-exchange (ion-exchange in general B01J) · CPC title

• C02F2101/20

  Heavy metals or heavy metal compounds · CPC title