Synthesis and characterization of a new series of cross-linked (phenol, formaldehyde, alkyldiamine) terpolymers for the removal of toxic metal ions from wastewater

Patent metadata

Field	Value
Publication number	US-2016332893-A1
Application number	US-201514712097-A
Country	US
Kind code	A1
Filing date	May 14, 2015
Priority date	May 14, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

Cross-linked terpolymers made up of phenol, diaminoalkane and formaldehyde monomeric units. The cross-linked terpolymers are synthesized via a Mannich mechanism in n-heptane, characterized with multiple spectroscopic techniques, scanning electron microscopy and powder X-ray diffraction, and are also investigated for their Pb 2+ adsorption capacity and thermodynamic properties. A method of removing Pb 2+ ions from an aqueous solution or a wastewater sample with these cross-linked terpolymers is also described.

First claim

1 : A cross-linked terpolymer comprising polycondensed units of phenol, diaminoalkane and formaldehyde;
wherein the diaminoalkane has a formula according to Formula 1:

with m, representing the number of carbon atoms in an alkyl chain, is 4, 6, 8 or 10; and
wherein each terminal amino group of the diaminoalkane unit bridges the aryl group of the phenol unit through a nitrogen-carbon-aryl linkage.

2 : The cross-linked terpolymer of claim 1 , wherein the cross-linked terpolymer has a formula according to Formula 2:

wherein n, representing the number of repeating units of the cross-linked terpolymer, is 10 to 10000.

3 : The cross-linked terpolymer of claim 1 , wherein the phenol, diaminoalkane and formaldehyde are present in the cross-linked terpolymer at a molar ratio of 1:2.5-3:y, wherein y≧6.

4 : The cross-linked terpolymer of claim 1 , wherein the diaminoalkane is at least one substituted and unsubstituted alkane selected from the group consisting of butane, hexane, octane and decane.

5 : The cross-linked terpolymer of claim 1 , further comprising one or more metal ions coordinated to one or more nitrogen atoms of the cross-linked terpolymer.

6 : The cross-linked terpolymer of claim 1 , wherein the cross-linked terpolymer or a solid material synthesized therefrom has a surface area of 0.01-0.15 m 2 g −1 .

7 : The cross-linked terpolymer of claim 1 , wherein the cross-linked terpolymer has an average molecular weight of 1,500-350,000 g/mol.

8 : A method of removing Pb 2+ ions from an aqueous solution or a real wastewater sample, comprising:
contacting the aqueous solution with an adsorbent comprising the cross-linked terpolymer of claim 1 .

9 : The method of claim 8 , wherein the contacting is carried out at a temperature of 25-50° C.

10 : The method of claim 8 , wherein the contacting is carried out at pH 5-6.

11 : The method of claim 8 , wherein the contacting is carried out for 1-5 h.

12 : The method of claim 8 , wherein the cross-linked terpolymer has a Pb 2+ adsorption capacity of at least 10 mg L −1 based on the total volume of the aqueous solution.

13 : The method of claim 8 , wherein the cross-linked terpolymer has a Pb 2+ maximum adsorption capacity of 1-250 mg g −1 based on the total weight of the cross-linked terpolymer.

14 : The method of claim 8 , wherein the contacting removes at least 85% of the Pb 2+ ions present in the aqueous solution.

15 : The method of claim 8 , wherein after contacting, one or more Pb 2+ ions are coordinated to one or more nitrogen atoms of the adsorbent.

16 : The method of claim 8 , further comprising removing at least one metal ion selected from the group consisting of Co, Cu, Zn, As, Sr, Mo, Cd and Hg from the aqueous solution.

17 : A method of preparing the cross-linked terpolymer of claim 1 , comprising:
polycondensing phenol, diaminoalkane and formaldehyde to form a terpolymer; and curing the terpolymer to form the cross-linked terpolymer.

18 : The method of claim 17 , wherein the polycondensing is carried out by stirring and heating a mixture comprising the phenol, the diaminoalkane, the formaldehyde and a reaction medium to 85-95° C.

19 : The method of claim 17 , wherein the reaction medium is n-heptane.

20 : The method of claim 17 , wherein the curing is carried out by continuously stirring the terpolymer at 85-95° C. for 8-24 h.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al Hamouz Othman Charles Sadeq

Classifications

• B01J20/28059

  being less than 100 m2/g · CPC title

• B01J20/264

  derived from different types of monomers, e.g. linear or branched copolymers, block copolymers, graft copolymers · CPC title

• B01J20/267

  Cross-linked polymers · CPC title

• C02F1/285 Primary

  using synthetic organic sorbents · CPC title

• C02F2101/20

  Heavy metals or heavy metal compounds · CPC title