Fluorinated ether compositions and methods of using the same

A polymer or oligomer comprising at least one first divalent unit represented by formula:

• wherein
• each Rf is independently selected from the group consisting of:
• Rfa—(O)t—CHF—(CF2)n—;
• [Rfa—(O)t—C(L)H—CF2—O]m—W—;
• CF3CFH—O—(CF2)p—;
• and
• CF3—O—(CF2)3—(OCF(CF3)—CF2),z—O-L1-;
• each Q is independently selected from the group consisting of a bond, —C(O)—N(R1)—, and —C(O)—O—;
• each X is independently selected from the group consisting of alkylene and arylalkylene, wherein alkylene and arylalkylene are each optionally interrupted by at least one ether linkage and optionally terminated by —N(R1)—C(O)— or —O—C(O)—;
• R and R1 are each independently selected from the group consisting of hydrogen and alkyl having from 1 to 4 carbon atoms;
• Rfa represents a partially or fully fluorinated alkyl group having from 1 to 10 carbon atoms and optionally interrupted with at least one oxygen atom;
• L is selected from the group consisting of F and CF3;
• W is selected from the group consisting of alkylene and arylene;
• L1 is selected from the group consisting of —CF2—, —CF2CF2—, and —CF(CF3)—;
• t is 0 or 1, wherein when Rf is represented by formula Rfa—(O)t—CHF—(CF2)n— and t is 0, then Rfa is interrupted with at least one oxygen atom;
• m is 1, 2, or 3;
• n is 0 or 1;
• each p is independently an integer from 1 to 6;
• and
• z is an integer from 0 to 3.