. . . "where L is a leaving group, R6 is a covalent bond or a multi-valent organic group, Z is a branch point, P2 is long-chain polymer, Y is a proton, a weak functional group, or a selective functional group, and m is an integer that is equal to the valency of Z minus one, where the weak functional group includes groups that interact with filler via through-space interaction or groups that interact with" .