A reaction product of a compound having a structure represented by Formula I: (G)n -R-(X--CF═CF2)m wherein R represents an optionally substituted hydrocarbyl group, X represents any group which links R and a perfluorovinyl group; n is the number of G groups, m is a number of --(XCF???CF2) groups, and G represents any reactive functional group or a group convertible into a reactive functional