Perfluoroalkyl halides and derivatives

In combination with a fibrous substrate, a polymer comprising units of the formula R.sub.fsb -(Z) resulting from the polymerization of monomer R.sub.fsb -(Z.sub.m), wherein R.sub.fsb represents a plurality of perfluoroalkyl groups pendant from Z, wherein some of said plurality of perfluoroalkyl groups are straight chain and some of said plurality of perfluoroalkyl groups are branched chain, and wherein about 60 to about 90% of the perfluoroalkyl groups in said polymer are straight chain and about 10 to about 40% of the perfluoroalkyl groups in said polymer are branched chain.

An aqueous composition, comprising:

• a polymer having first and second interpolymerized units, wherein said first unit comprises a straight chain perfluoroalkyl group, wherein said second unit comprises a branched chain perfluoroalkyl group, and
• wherein about 65 to about 85% of the perfluoroalkyl groups on said polymer are straight chain and about 15 to about 35% of the perfluoroalkyl groups on the polymer are branched chain.

An aqueous composition, comprising:

• a polymer having at least one repeating unit having both branched and straight chain perfluoroalkyl groups;
• wherein about 60 to about 90% of said perfluoroalkyl groups on said polymer are straight chain and about 10 to about 40% of said perfluoroalkyl groups on said polymer are branched chain.

In combination with an aqueous solution, a surfactant, comprising:

• a polycarbodiimide having a plurality of pendant saturated perfluoroalkyl groups;
• wherein about 60 to about 90% of said perfluoroalkyl groups are straight chain and about 10 to about 40% of said perfluoroalkyl groups are branched chain.