A compound comprising Formula 2A, 2B, or 2C TABLE-US-00001 (R.sub.a--O--CO--).sub.2Y Formula 2A R.sub.a--O--CO--Y--CO--O--(CH.sub.2CH.sub.2)R.sub.f Formula 2B R.sub.a--O--CO--Y--CO--O--R Formula 2C wherein R.sub.a is the group (i) R.sub.f(CH.sub.2CF.sub.2).sub.d--(C.sub.gH.sub.2g)--; (ii) R.sub.fOCF.sub.2CF.sub.2--(C.sub.gH.sub.2g)--; (iii) R.sub.f OCFHCF.sub.2O(CH.sub.2CH.sub.2O).sub.v--(C.sub.gH.sub.2g)--; (iv) R.sub.fOCFHCF.sub.2O(C.sub.wH.sub.2w)--; (v) R.sub.fOCF(CF.sub.3)CONH--(C.sub.gH.sub.2g)--; or (vi) R.sub.f(CH.sub.2).sub.h[(CF.sub.2CF.sub.2).sub.i(CH.sub.2CH.sub.2).sub.j]- .sub.k; each R.sub.f is independently C.sub.cF.sub.(2c+1); c is 2 to about 6; d is 1 to about 3; g is 1 to 4; v is 1 to about 4; w is from about 3 to about 12; h is 1 to about 6; i, j, and k are each independently 1, 2, or 3, or a mixture thereof; provided that the total number of carbon atoms in group (vi) is from about 8 to about 22; Y is a linear or branched diradical having olefinic unsaturation of the formula --C.sub.eH.sub.(2e-2)-- wherein e is 2 or 3; R is H or a linear or branched alkyl group C.sub.bH.sub.(2b+1)--; and b is from 1 to about 18.