ut 10 for each (Cs H2s O), t is an integer of 1 to about 6, and p is an integer of 0 to about 4; Rf a is selected from the group consisting of --Cx F2x O)z Cy F2y+1, --Cq F2q X, and --Cq F2q-2 X, preferably --(Cx F2x O)z Cy F2y+1, where x is independently an integer of 1 to about 10 (preferably 1 to about 4) for each Cx F2x O group, y is an integer of 1 to about 10 (preferably 1 to about 6), z is