Pbi modification and cross-linking methods

Abstract

The present disclosure provides methods for modifying and cross-linking polybenzimidazoles, PBI. In one embodiment, the polybenzimidazole reacts with a compound, which has a halogen and a double bond functionality and which comprises a halogen and an organic group to form modified polymers by means of a nucleophilic substitution of the amine proton of the benzimidazole functionality in a solution, and a functional group is connected via each resulting free double bond and/or the polymers that are thus modified are cross-linked.

1 . A method for modification and cross-linking of polybenzimidazole (PBI) having the structure 
       
         
           
           
               
               
           
         
       
       wherein the polybenzimidazole reacts in a solution with a compound having a halogen and a double bond functionality of the type 
       
         
           
           
               
               
           
         
       
       where X is a halogen and R an organic group through a nucleophilic substitution of the amine protons of the benzimidazole functionality to obtain the modified polymers 
       
         
           
           
               
               
           
         
       
       where the resulting free double bonds are connected in each case to a functional group and/or cross-linking of the modified polymers occurs. 
     
     
         2 . Method according to  claim 1 , wherein the cross-linking between two modified polymers occurs. 
     
     
         3 . Method according to  claim 1 , wherein in that the cross-linking between two modified polymers occurs by means of a cross-linking molecule having at least two double bonds. 
     
     
         4 . Method according to  claim 1 , characterized in wherein the cross-linking of two modified polymers is via two double bonds. 
     
     
         5 . A method according to  claim 1 , wherein at least one functional group having a double bond is connected to a modified polymer. 
     
     
         6 . A method according to  claim 5 , wherein the functional group has high proton conductivity. 
     
     
         7 . A method according to  claim 5 , wherein the functional group is an amine group. 
     
     
         8 . A method according to  claim 5 , wherein the functional group is based on an ionic liquid. 
     
     
         9 . A method according to  claim 5 , wherein the functional group reduces the degree of crystallinity of the polybenzimidazole. 
     
     
         10 . A method according to  claim 1 , wherein a monomer having a double bond is connected to the double bond of a modified polymer. 
     
     
         11 . A modified polybenzimidazole polymer comprising repeat units of formula 
       
         
           
           
               
               
           
         
         wherein at least one of the nitrogen atoms of the repeat units is covalently bound to a compound of formula 
       
       
         
           
           
               
               
           
         
         wherein R′ is an organic group. 
       
     
     
         12 . The modified polybenzimidazole polymer of  claim 11 , wherein R′ is alkyl. 
     
     
         13 . The modified polybenzimidazole polymer of  claim 11 , wherein R′ is —CH 2 —. 
     
     
         14 . A crosslinked polybenzimidazole polymer produced from the modified polybenzimidazole polymer of  claim 11 . 
     
     
         15 . A modified polybenzimidazole polymer having the structure 
       
         
           
           
               
               
           
         
       
     
     
         16 . A crosslinked polybenzimidazole polymer produced from the modified polybenzimidazole polymer of  claim 15 . 
     
     
         17 . A crosslinked polybenzimidazole polymer having the structure 
       
         
           
           
               
               
           
         
       
       wherein C-L includes a crosslinker produced by coupling any one or two of: an allyl group, vinylphosphonic acid, 1-allyl-3-methylimidazolium chloride, an amine group, allyl benzene, allyl p-toluol sulfate, and triallyl isocyanurate. 
     
     
         18 . The crosslinked polybenzimidazole polymer of  claim 17 , wherein the crosslinker includes triallyl isocyanurate. 
     
     
         19 . The crosslinked polybenzimidazole polymer of  claim 17 , wherein the polymer has a failure temperature of about 528° C. 
     
     
         20 . The crosslinked polybenzimidazole polymer of  claim 17 , wherein the polymer has a significantly higher modulus of elasticity at high temperatures, compared to an unmodified polybenzimidazole polymer.