Study of the structure-reactivity relationships in the photoinitiated cationic polymerization of epoxide monomers

The rates of the photoinitiated cationic polymerization of a variety of different structurally diverse open-chain, terminal, internal and cycloaliphatic epoxide monomers were determined using real-time Fourier transform infrared spectroscopy. The results were compared and an attempt was made to correlate the reactivity of the monomers with their structures. The effects of such factors as steric hindrance, intramolecular side reactions and the formation of crosslinked networks ape discussed. A general conclusion can be made that the polymerizations of cycloaliphatic epoxides are more rapid than all the other types of epoxy monomers and that within this class of monomers, steric hindrance plays a major role in determining the order of reactivity.