Destructable fluorinated alkoxysilane surfactants and repellent coatings derived therefrom

The fluorocarbylalkoxysilane according to claim I comprising at least one of the formulae:

• ##STR19## wherein:
• each A is independently 1) a covalent bond, or 2) a divalent hydrophilic group (a) having the formula
• (CHR.sup.2 --CH.sub.2 O).sub.q
• in which q is a number having a value of 1 to 40, preferably 2 to 10, R.sup.2 is hydrogen or methyl, and that at least 70% of R.sup.2 is hydrogen, or (b) derived from a polyol or its alkyl ether or polyether derivative by removal of one OH and one hydroxyl hydrogen;
• B is a divalent organic connecting group joining Si to R.sub.f or R.sub.f.sup.1 that is substantially stable against hydrolysis;
• R.sub.f is a monovalent polyfluoroaliphatic group having at least 2 carbon atoms and at least 30 weight percent fluorine;
• R.sub.f.sup.1 is a divalent polyfluoroaliphatic group having at least 6 carbon atoms and at least 30 weight percent of fluorine;
• R.sup.1 is an alkyl group having 1 to 18 carbon atoms or phenyl;
• R.sup.2 is hydrogen, or methyl, no more than 30% of R.sup.2 being methyl;
• R.sup.3 is independently hydrogen or lower alkyl group having I to 4 carbon atoms;
• m independently is an integer having a value of 1, 2, or 3;
• n independently is zero or an integer having a value of 1 or 2;
• m+n has a sum total value of 1, 2, or 3;
• with the provisos that at least one of A is a divalent hydrophilic group as previously disclosed and that the balance of R.sub.f or R.sub.f.sup.1 groups to said hydrophilic groups is such that a one percent by Weight mixture of the surfactant in water has a cloud point in the range of 0.degree. C. to 100.degree. C.