Modified polyamine membrane

Abstract

A modified polyamide membrane and method for making and using the same. The present invention includes many embodiments including methods comprising contacting a polyamide membrane with certain modifiers, including but not limited to certain oxazoline and/or thiazoline-based compounds, derivatives and polymers thereof. In one embodiment, the surface of a polyamide membrane is coated with a solution including a polyoxazoline and optionally a polyalkylene oxide material, followed by optional heating. Preferred embodiments may exhibit improved performance, e.g. increased rejection of certain species, (e.g. sodium chloride and/or boric oxides such as boric acid or various borate salts), reduced fouling, improved antimicrobial properties, and/or improved storage stability.

1 . A method of modifying a polyamide membrane comprising the step of contacting the polyamide membrane with a material selected from at least one of: compounds represented by Formula (I), and polymers derived therefrom: 
       
         
           
           
               
               
           
         
       
       wherein:
 R 1 , R 2 , R 3  and R 4  are each the same or different and are independently selected from: hydrogen, halogen, an alkyl group having from 1 to 4 carbon atoms, and an aryl group; 
 Y is selected from oxygen and sulfur; and 
 Z is a ring activating group. 
 
     
     
         2 . The method of  claim 1  comprising the step of applying a solution comprising the material of  claim 1  to at least a surface portion of the polyamide membrane. 
     
     
         3 . The method of  claim 2  comprising the step of heating the polyamide membrane after the application of solution. 
     
     
         4 . The method of  claim 1  wherein R 1 , R 2 , R 3  and R 4  are each hydrogen, and Y is oxygen. 
     
     
         5 . The method of  claim 1  wherein Z is selected from: hydrogen, an alkyl group having from 1 to 20 carbon atoms, an aryl group, and a polyalkylene oxide group. 
     
     
         6 . The method of  claim 1  wherein the material comprises a poly(oxazoline). 
     
     
         7 . The method of  claim 6  wherein the material comprises poly(2-ethyl-2-oxazoline). 
     
     
         8 . The method of  claim 1  comprising the step of contacting the polyamide membrane with a polyalkylene oxide material. 
     
     
         9 . The method of  claim 1  wherein the polyamide membrane is coated with an aqueous-based solution comprising a poly(oxazoline) and a polyalkylene oxide material. 
     
     
         10 . The method of  claim 1  wherein the polyamide membrane is contacted with a reaction product of a poly(oxazoline) and a polyalkylene oxide material. 
     
     
         11 . The method of  claim 1  wherein the polyamide membrane is contacted with a reaction product of a poly(oxazoline) and a polyfunctional epoxide material. 
     
     
         12 . The method of  claim 1  wherein the material comprises a polymer comprising a repeating unit represented by Formula (II): 
       
         
           
           
               
               
           
         
       
       wherein n is an integer from 2 to 20,000. 
     
     
         13 . The method of  claim 12  wherein R 1 , R 2 , R 3  and R 4  are each hydrogen, Y is oxygen and n is an integer from about 50 to 10,000. 
     
     
         14 . The method of  claim 12  wherein Z is selected from: hydrogen, an alkyl group having from 1 to 20 carbon atoms, an aryl group and a polyalkylene oxide group. 
     
     
         15 . The method of  claim 12  wherein Z is selected from: aniline, benzene-1,3-diamine, hydroxyl, quaternary ammonium and a polybiocide. 
     
     
         16 . The method of  claim 12  wherein the polymer comprises an end group which is chemically reactive. 
     
     
         17 . The method of  claim 12  wherein the polymer comprises an end group selected from: hydroxyl, epoxy, and ethylene glycol. 
     
     
         18 - 23 . (canceled) 
     
     
         24 . The method of  claim 12  wherein equal to or less than about 10 weight percent of said polymer comprises a repeating unit of alkylene oxide represented by Formula (III): 
       
         
           
           
               
               
           
         
       
       wherein X is a carbon atom or a chemical bond; and R 4  is selected from: hydrogen, alkyl group comprising 1 to 4 carbon atoms, hydroxyl group, and a hydroxylalkyl group having from 1 to 4 carbon atoms. 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 12  wherein said polymer is a reaction product of a polymer having a repeating unit represented by Formula II and a polymer having a repeating unit represented by Formula III. 
     
     
         27 - 29 . (canceled) 
     
     
         30 . The method of  claim 1  wherein said membrane further comprises a microporous support.