Composite polyamide membrane post treated with nitrious acid

Patent metadata

Field	Value
Publication number	US-9808769-B2
Application number	US-201415030919-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Dec 2, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A method for making a composite polyamide membrane including a porous support and a thin film polyamide layer, wherein the method includes: (i) applying a polar solution comprising a polyfunctional amine monomer and a non-polar solution comprising a polyfunctional acyl halide monomer to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer; (ii) treating the thin film polyamide layer with a polyfunctional arene compound; and (iii) exposing the thin film polyamide layer to nitrous acid; wherein the polar and non-polar solutions further comprises at least one of the following: (A) at least one of the solutions further comprises a tri-hydrocarbyl phosphate compound represented by Formula (I): and (B) the non-polar solution further comprises an acid-containing monomer comprising a C 2 -C 20 hydrocarbon moiety substituted with at least one carboxylic acid functional group or salt thereof and at least one amine-reactive functional group.

First claim

The invention claimed is:

1. A method for making a composite polyamide membrane comprising a porous support and a thin film polyamide layer, wherein the method comprises:
i) applying a polar solution comprising a polyfunctional amine monomer and a non-polar solution comprising a polyfunctional acyl halide monomer to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer;
ii) treating the thin film polyamide layer with a polyfunctional arene compound comprising 1 or 2 benzene rings collectively substituted with the follow four functional groups:
(a) a first functional group (w) selected from the group consisting of: —NR 4 R 5 and —OH,
(b) a second functional group (x) selected from the group consisting of: —NR 4 R 5 , —OH, —COOH, and-SO 3 H,
(c) a third functional group (y) is selected from the group consisting of: —H, —NR 4 R 5 , —OH, —COOH, and —SO 3 H,
(d) a fourth functional group (z) selected from the group consisting of: —H, —CH 3 , —NR 4 R 5 , —OH, —COOH and —SO 3 H,
wherein: (R 4 ) and (R 5 ) are independently selected from the group consisting of: —H and hydrocarbyl groups comprising from 1 to 10 carbon atoms; and
iii) exposing the thin film polyamide layer to nitrous acid;
wherein step ii) may occur before, during or after step iii) and, wherein the method is characterized by:
(A) at least one of the polar and non-polar solutions further comprises a tri-hydrocarbyl phosphate compound represented by Formula I:

wherein R 1 , R 2 and R 3 are independently selected from the group consisting of: hydrogen and hydrocarbyl groups comprising from 1 to 10 carbon atoms, with the proviso that no more than one of R 1 , R 2 and R 3 are hydrogen; and
(B) the non-polar solution further comprises an acid-containing monomer comprising a C 2 -C 20 hydrocarbon moiety substituted with at least one carboxylic acid functional group or salt thereof and at least one amine-reactive functional group selected from the group consisting of: acyl halide, sulfonyl halide and anhydride, wherein the acid-containing monomer is distinct from the polyfunctional acyl halide monomer.

2. The method of claim 1 wherein the polyfunctional arene compound is represented by at least one of:

wherein (L) is selected from the group consisting of: a bond between the rings, an alkylene group comprising from 1 to 6 carbon atoms and an oxyalkylene group comprising from 1 to 6 carbon atoms.

3. The method of claim 1 wherein the non-polar solution comprises an acid-containing monomer which comprises an arene moiety.

4. The method of claim 1 wherein the non-polar solution comprises an acid-containing monomer that comprises an aliphatic moiety.

5. The method of claim 1 wherein the non-polar solution comprises an acid-containing monomer that comprises at least two amine-reactive functional groups.

6. The method of claim 1 wherein the thin film polyamide layer has a dissociated carboxylic acid content of at least 0.18 moles/kg at pH 9.5 as measured by Rutherford Backscattering prior to the step of exposing the thin film polyamide layer to nitrous acid.

7. The method of claim 1 wherein:
(w) is selected from the group consisting of: —NR 4 R 5 and —OH,
(x) is selected from the group consisting of: —COOH and —SO 3 H,
(y) is selected from the group consisting of: —H, —COOH and —SO 3 H,
(z) is selected from the group consisting of: —H, —CH 3 , —COOH, and —SO 3 H, and
(R 4 ) and (R 5 ) are independently selected from the group consisting of: —H and hydrocarbyl groups comprising from 1 to 10 carbon atoms.

8. The method of claim 1 wherein:
(w) is selected from the group consisting of: —NR 4 R 5 ,
(x) is selected from the group consisting of: —OH,
(y) selected from the group consisting of: —H, —COOH, and —SO 3 H,
(z) selected from the group consisting of: —H, —CH 3 , —COOH, and —SO 3 H, and
(R 4 ) and (R 5 ) are independently selected from the group consisting of: —H and hydrocarbyl groups comprising from 1 to 10 carbon atoms.

9. The method of claim 1 wherein:
(w) and (x) are selected from the group consisting of: —NR 4 R 5 ,
(y) and (z) are selected from the group consisting of: —H, and
(R 4 ) and (R 5 ) are independently selected from the group consisting of: —H and hydrocarbyl groups comprising from 1 to 10 carbon atoms.

Assignees

• Dow Global Technologies Llc

Inventors

• Paul Mou
• Roy Abhishek
• Tomlinson Ian A

Classifications

• B01D71/56

  Polyamides, e.g. polyester-amides · CPC title

• B01D2325/20

  Specific permeability or cut-off range · CPC title

• B01D2323/40

  in-situ membrane formation · CPC title

• B01D67/0006

  by chemical reactions (in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125) · CPC title

• B05D3/108

  Curing · CPC title