Curing reaction of glycidylthioether resins: Kinetic model study by near infrared spectroscopy and multivariate curve resolution

Abstract

The reactivity of sulfur‐based epoxy monomers was studied by monitoring of a model system involving phenylglycidylthioether and aniline. The reaction was carried out under isothermal conditions and monitored in situ by near infrared spectroscopy. Using multivariate curve resolution‐alternating least squares made it possible to obtain the concentration and spectral profiles of each species throughout the reaction. To obtain the kinetic rate constants, the values of the recovered concentration profiles were fitted to a kinetic model proposed for the reaction. Reactivity was evaluated by comparing the concentration profiles and kinetic rate constants obtained with the same parameters obtained for phenylglycidylether/aniline as a reference system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4846–4856, 2006

Synthesis and characterisation of new sulphur-containing epoxy networks

“…Model curing studies of glycidylthioether epoxy resin with aniline have been studied using near-infrared spectroscopy (NIRS), and it was concluded that the cure mechanism was similar to typical glycidylether epoxy resins. 22 They did find however that the thioether species reacted more slowly and attributed this to the lower electronegativity of the sulphur atom, inhibiting the epoxy ring opening.…”

Study of the Infrared Spectral Features of an Epoxy Curing Mechanism

“…Although the curing mechanisms [1][2][3]6,7,[10][11][12][13][14][15][16][18][19][20][21][22][23][24] and the kinetics of curing reaction 1,6,11,13,14,[16][17][18][19][20][21][22]24,33,[36][37][38][39][40][41][42][43] according to NIR spectra have been widely reported, the sequence of the change of the bands, which may reveal the reaction mechanism at the molecular level, has not been accurately described. In addition, due to the obscure band assignments resulting from simultaneous occurrence of a variety of fundamental and overtone transitions in the epoxy curing process, not all the bands in NIR spectra have been clearly assigned.…”

Processing

“…An example for the application of multivariate curve resolution to analyze time-dependent sets of NIR spectra obtained during the curing of a glycidylthioether resin has recently been described by Garrido et al [21]. The authors used this approach to follow the concentration profiles of phenylglycidylthioether (PGTE), aniline, secondary and tertiary amines, neatly at different starting concentrations of aniline.…”

“…For instance, the conversion in photo-polymerization of acrylate coatings was measured in-situ [18] on thin polymer sheets by NIR spectroscopy and the thickness of the coating was also determined [19,20]. The curing of epoxy resin was studied with NIR [21]. A laid fabric pre-impregnated with epoxy resin was studied by NIR, and it was possible to determine both the resin content and the volatile content of the pre-preg quickly (with a measurement time of 30 s) and with high accuracy [22].…”