A copolymer comprises repeating units derived from at least one
co-reactant comprising two or more mercapto functional groups, and
repeating units derived from a fluoroacrylate comprising the reaction
product of: (a) at least one fluorochemical alcohol represented by the
formula: C.sub.4F.sub.9--X--OH wherein: ##STR00001## R=hydrogen or
an alkyl group of 1 to 4 carbon atoms, m=2 to 8,
R.sub.f=C.sub.nF.sub.2n+1, n=1 to 5, y=0 to 6, and q=1 to 8; (b) at
least one unbranched symmetric diisocyanate; and (c) at least one
hydroxy-terminated alkyl (meth)acrylate or 2-fluoroacrylate monomer
having 2 to about 30 carbon atoms in its alkylene portion.