g perfluorinated monomer units having the structure (--CF2 O--), (--CF2 CF2 O--), or combinations thereof, cross-linked with a cross-linking agent, (ii) a perfluorinated urethane polymer precursor having the structural formula ##STR9## which has been cured with a photoinitiator in the presence of a radiation, wherein n is an integer in the range of 0 to 6 inclusive, and (iii) an epoxy-terminated p