## wherein Rf is F (CF.sub.2 -CF.sub.2).sub.3-8 ; R is (CH.sub.2).sub.x wherein x is an integer of 1 to 4;R.sup.1 is lower alkyl of 1 to 6 carbon atoms, aryl or substituted aryl; andR.sup.2 is lower alkyl of 1 to 6 carbon atoms.DETAILED DESCRIPTIONA preferred surfactant has the following formula: ##STR3## wherein R and Rf are as defined above and R.sup.3 is lower alkyl of 1 to 6 carbon atoms;The m