Study on the effect of rare earth metal triflates as initiators in the cationic curing of DGEBA/γ-valerolactone mixtures and characterization of the thermosets obtained

The thermal cationic curing of mixtures in different proportions of diglycidylether of bisphenol A (DGEBA) with gamma-valerolactone (gamma-VL) initiated by scandium, ytterbium and lanthanum triflates or a conventional BF3-MEA initiator was investigated. The non-isothermal differential scanning calorimetry (DSC) experiments at a controlled heating rate were used to evaluate the evolution of the reactive systems. BF3-MEA and rare earth metal triflates initiated curing systems follow a different evolution. Among rare earth metal triflates tested, the scandium was the most active initiator. The phenomenological changes that take place during curing were studied and represented in a time-temperature-transformation (TTT) diagram. Some characteristics of the materials were also evaluated. (c) 2008 Elsevier Ltd. All rights reserved.