Photopolymerizations of 3,4-epoxycyclohexylmethyl-3',4-epoxycyclohexane carboxylate (ECH) and triethyleneglycol methyl vinyl ether (TEGMVE) and their mixtures catalyzed with diaryliodonium hexafluoroantimonate (IA) were studied. Rates of polymerizations for mixtures of monomers are different from those for both homopolymerizations. The photocured mixtures showed a single not dual glass transition temperature over all composition ratios. During SEC analysis, the soluble fraction of the photocured equimolar mixture did not show any peaks that the homopolymer of TEGMVE showed, which means that TEGMVE was incorporated into a polymer network. Real-time FT-IR spectroscopy showed that ECH and TEGMVE did not polymerize independently for polymerizations of mixtures of ECH and TEGMVE. C-13 NMR spectroscopy showed strong evidence that cross-propagation reaction occurs. All of the above suggest that the copolymerization takes place during the photoinitiated cationic polymerization of ECH and TEGMVE mixtures. (C) 2003 Elsevier Ltd. All rights reserved.