ESR of spin-labeled cross-linked perfluoropolyethers and properties of adsorbed water

Crosslinked perfluoro polyethers are studied in the form of their spin-labeled adducts and after swelling with water solutions containing small nitroxide radicals. The analysis of the SER line shapes revealed a relatively high flexibility of the perfluoro ether backbone. Formation of water pools in the polymer network was suggested on the basis of the ESR results, and the rheological properties of the swelling water were similar to those of water adsorbed in other perfluorinated ionomers