Process for dissolution of highly fluorinated ion-exchange polymers
View Patent ↗Highly fluorinated ion-exchange polymers achieve dissolution in aqueous tetrahydrofuran at lower pressures and temperatures than in other solvents, with few or no side products being formed.
1. A liquid composition consisting essentially of ion-exchange polymer in aqueous tetrahydrofuran, at least about 50% of the total number of halogen and hydrogen atoms in said ion-exchange polymer being fluorine atoms, said aqueous tetrahydrofuran being from about 10:90 weight % water:tetrahydrofuran to about 90:10 weight % water:tetrahydrofuran.
2. The liquid composition of claim 1 wherein the aqueous tetrahydrofuran is from about 45:55 weight % water:tetrahydrofuran to about 55:45 weight % water:tetrahydrofuran.
3. The liquid composition of claim 1 wherein said ion-exchange polymer is in the acid form.
4. The liquid composition of claim 1 wherein said ion-exchange polymer is about 1 to about 15 weight % of the combined weights of the polymer and aqueous tetrahydrofuran.
5. The liquid composition of claim 1 wherein said ion-exchange polymer is perfluorinated.
6. The liquid composition of claim 1 wherein said ion-exchange polymer has an ion-exchange ratio of about 3 to about 33.
7. The liquid composition of claim 1 wherein said ion-exchange polymer has an ion-exchange ratio of about 8 to about 23.
8. The liquid composition of claim 1 wherein said composition contains less than about 3 weight % organic materials other than said tetrahydrofuran and those associated with said ion exchange polymer.