Polymerization of an epoxy/dimethacrylate hybrid system photoinitiated by CQ/amine/iodonium salt.

ASMUSSEN, SILVANA; WALTER F SCHROEDER; IGNACIO DELL' ERBA; CLAUDIA I. VALLO

Ciudad Autónoma de Buenos Aires

Simposio; X Simposio Argentino de Polímeros; 2013

Universidad de Buenos Aires, Universidad Nacional de La Plata, INTI, e ITBA (Instituto Tecnológico de Buenos Aires)

Raman and near-infrared spectroscopies were used to monitor the individual monomer photopolymerization within the hybrid epoxy/methacrylate system based on a cycloaliphatic epoxy (3,4-epoxycyclohexylmethyl 3?,4?-epoxycyclohexane carboxylate) and an aromatic dimethacrylate (2,2-bis[4-(2-methacryloxyethoxy) phenyl]propane). Epoxy/methacrylate systems at mass fractions 50:50 and 75/25 were studied. The resins were activated for visible light polymerization by the addition of a three-component photoinitiator system composed of the camphorquinone/amine pair in combination with an iodonium salt. The rate of polymerization and final conversion degree of the methacrylate groups were raised when the dicycloepoxide monomer was present. This is explained in terms of an enhancement of the mobility of the reactive species caused by the presence of the epoxy monomer. Conversely, the conversion of epoxy groups in the mixtures was markedly reduced in comparison with the final conversion of the neat resin. This is attributed to the earlier vitrification of the system due to the faster polymerizing methacrylate network.