Sulfonated-Perfluorocyclobutane Polyelectrolyte Membranes for Fuel Cells

Abstract

A process for preparing a polymer comprising sulfonating a perfluorocyclobutane polymer with a sulfonating agent to form a sulfonated perfluorocyclobutane polymer, wherein the sulfonating agent comprises oleum, SO 3 or a combination thereof is provided. A process for preparing proton exchange membranes and fuel cells comprising the proton exchange membrane are also provided.

1 .- 13 . (canceled) 
     
     
         14 . A fuel cell comprising:
 a proton exchange membrane comprising an ion conducting polymer, the ion conducting polymer comprising a repeat unit described by the following formula:   
       
         
           
           
               
               
           
         
       
       the repeat unit being sufficiently sulfonated that the proton exchange membrane has an ion exchange capacity between 1.4 and 1.9 meq of sulfonic acid;
 an anode flowfield portion; and 
 a cathode flowfield portion, the anode flowfield portion and cathode flowfield portion being disposed on opposite sides of the proton exchange membrane. 
 
     
     
         15 . The fuel cell of  claim 14  wherein the repeat unit is repeated n times, n being from about 20 to about 500. 
     
     
         16 . The fuel cell of  claim 14  wherein each repeat unit comprises 0 to 2 sulfonic acid groups. 
     
     
         17 . A fuel cell comprising:
 a proton exchange membrane comprising an ion conducting polymer, the ion conducting polymer comprising a repeat unit described by the following formula:   
       
         
           
           
               
               
           
         
       
       the proton exchange membrane having an ion exchange capacity between 1.4 and 1.9 meq of sulfonic acid;
 an anode flowfield portion; and 
 a cathode flowfield portion, the anode flowfield portion and cathode flowfield portion being disposed on opposite sides of the proton exchange membrane. 
 
     
     
         18 . The fuel cell of  claim 17  wherein the ion conducting polymer comprises a polymer block wherein each repeat unit comprises 0 to 2 sulfonic acid groups. 
     
     
         19 . The fuel cell of  claim 17  wherein the repeat unit is repeated n times, n being from about 20 to about 500. 
     
     
         20 . A fuel cell comprising:
 a proton exchange membrane comprising an ion conducting polymer, the ion conducting polymer comprising a polymer described by the following formula:   
       
         
           
           
               
               
           
         
         the proton exchange membrane having an ion exchange capacity between 1.4 and 1.9 meq of sulfonic acid; 
         n is from about 20 to about 500. 
         an anode flowfield portion; and 
         a cathode flowfield portion, the anode flowfield portion and cathode flowfield portion being disposed on opposite sides of the proton exchange membrane.