Heterocycle grafted monomers and related polymers and hybrid inorganic-organic polymer membranes
View Patent ↗Polymers, polymer precursors, and other materials are described, having at least one heterocycle and being useful for fabrication of proton-exchange membranes (PEMs). In representative examples, the heterocycle is a fluorinated imidazole ring. The heterocycle can be chosen to have a low value of pKa, and may be a triazole ring, other nitrogen-containing heterocycle, or derivative thereof. Polymers and composites were prepared having excellent proton conductivity. Applications of these materials include fuel cells and other ion-conducting applications.
1. A proton-conducting polymer including:
a hybrid inorganic-organic matrix including silicon atoms;
an acid group attached to the hybrid inorganic-organic matrix; and
a nitrogen-containing heterocycle attached to the hybrid inorganic-organic matrix,
wherein the nitrogen-containing heterocycle is selected from a group consisting of 1,2,4-triazole, 1,2,3-triazole, 1H-benzotriazole, pyrimidine, pyrazine, purine, imidazole, pyrazole, and pyridine.
2. The proton-conducting polymer of claim 1 , wherein the nitrogen-containing heterocycle has at least one halogenated substituent group attached thereto.
3. The proton-conducting polymer of claim 1 , wherein the nitrogen-containing heterocycle has an electron-withdrawing group attached thereto.
4. The proton-conducting polymer of claim 3 , wherein the electron-withdrawing group includes at least one fluorine atom.
5. The proton-conducting polymer of claim 1 , wherein the nitrogen-containing heterocycle is a fluorinated imidazole ring having a pKa of less than approximately 2.6.