The thio-substituted dicarboxylic acid anhydrides which can be employed in this invention include members selected from the group consisting of monoanhydrides of the Formula (F): ##STR4## and polyanhydrides of the Formula (G): ##STR5## wherein J is divalent hydrocarbyl, J' is polyvalent hydrocarbyl, D3 comprises H or hydrocarbyl, and p is a number of greater than 1 (e.g., an average of from >1 to