Synthesis and polymerization studies of formaldehyde oxime and its derivatives

Formaldehyde oxime and three O-alkyl derivatives were examined as potential imine monomers. Formaldehyde oxime spontaneously polymerized below 60 degrees C and did not polymerize above 60 degrees C (ceiling temperature), even in the presence of free-radical or cationic initiators. The O-benzoyl derivative was isolated as the cyclic trimer but could not be converted into the monomeric form. Formaldehyde O-benzyloxime was synthesized and isolated. Attempted homopolymerizations in the presence of free-radical initiators only fed to oligomers, whereas with cationic initiators only cyclic trimer was obtained. Copolymerizations with appropriate vinyl monomers and free-radical and anionic initiators yielded only low molecular weight polymers. Cationic copolymerizations gave higher molecular weights and polymer yields, but the polymers containing appreciable amounts of imine function had very low molecular weights. We conclude that the polymerizability of imines is extremely sensitive to the substitution pattern: imines with only a substituent on nitrogen are unstable and readily polymerize, whereas imines with more substitutes generally do not polymerize. Electron-withdrawing substituents are more favorable to polymerizability. (C) 2000 John Wiley & Sons, Inc.