Composition comprising perfluoropolyether

A composition comprising an aryl perfluoropolyether which is a difunctional aryl perfluoropolyether having the formula of Rf1—[(Y)a—(CtR(u+v))—(O—CtR1(u+v))b—R]2 wherein

• Rf1 has a formula weight of about 400 to about 15,000;
• Rf1 is —(CF2CF2O)e(CF2O)fCF2—, —(C3F6O)p(CF2CF2O)q(CFXO)rCF2—, —(CF2CF2O)(C3F6O)wCF(CF3)—, —CF(CF3)O(C3F6O)w—Rf2—O(C3F6O)wCF(CF3)—, —((CQ2)CF2CF2O)sCF2CF2—, or combinations of two or more thereof;
• where
• the units with formulae CF2CF2O and CF2O are randomly distributed along the chain;
• X is —F, —CF3, or combinations thereof;
• e and f are numbers such that the e/f ratio ranges from about 0.3 to about 5;
• each Q is independently —F, —Cl, or —H;
• p, q and r are numbers such that (p+q) ranges from 1 to 50 and r/(p+q) ranges from 0.1 to 0.05;
• each w is independently 2 to 45;
• Rf2 is linear or branched —CmF2m—;
• m is 1-10;
• s is an average number such that the formula weight of Rf1 ranges from 400 to 15,000;
• each R is independently —H, —OH, —SO3M, NR32, —NO2, —R4OH, —R4SO3M, —R4NR32, —R4NO2, —R4CN, —C(O)OR4, —C(O)OM, —C(O)R4, —C(O)NR32, or combinations of two or more thereof;
• except that when b=0, R cannot be four hydrogen atoms and —OH, or —Br, or —NH2;
• or R cannot be solely H or —NO2, or combinations thereof;
• each R1 is independently H, —OH, —SO3M, —NR32, —NO2, —CN, —R4OH, —R4SO3M, —R4NR32, —R4NO2, —R4CN, —C(O)OR4, —C(O)OM, —C(O)R4, —C(O)NR32, or combinations of two or more thereof provided that if b=0, the combination of R and R1 cannot be four or more hydrogen atoms and —OH, —NH2, or —NO2;
• each R3 is independently H, C1-C10 alkyl, or combinations of two or more thereof;
• R4 is a C1-C10 alkyl;
• M is a hydrogen or metal ion wherein the metal ion is selected from the group consisting of alkali metal, alkaline earth metal, transition metal, or combinations of two or more thereof;
• a is 0 or 1;
• b is 0-5;
• Y is a divalent radical —CH2OCH2—, —(CH2)o—O—, —(CF2)n—, —CF2O—, —CF2OCF2—, —C(O)—, —C(S)—, or combinations of two or more thereof;
• n is about 1 to about 5;
• o is about 2 to about 5;
• t is equal to 6+u;
• u is any combination of 0, 2, 4, 6, 8, 10, 12, 14, 16;
• and
• v is independently either 2 or 4.