Polymer catalyzed reactions: The remarkable self-catalyzed solubilization of crosslinked 4-vinylpyridine-ethylene dimethacrylate resins

Several crosslinked polymers containing 4-vinylpyridine moieties were prepared and partly quaternized for testing in various catalytic applications. Unlike other copolymers crosslinked with ethylene dimethacrylate, the partly quaternized copolymers are found to be extremely sensitive to alkali and dissolve readily, even at crosslinking densities exceeding 10%. A study of the mechanism of this self-catalyzed degradation shows that pyridinium methide units located on the main chain of the polymer in the vicinity of the ethylene dimethacrylate crosslinks are responsible for the cleavage process. This study confirms the great mobility of polymer segments and the reactivity of sites located at or near the crosslinks of highly reticulated resins.