Cationic copolymerization of DGEBA with two bicyclic bis(γ-lactone) derivatives using rare earth metal triflates as initiators

The thermal cationic curing of mixtures in different proportions of diglycidylether of bisphenol A (DGEBA) with two differently substituted condensed bis(γ-lactone)s (BisMe and BisPhe) initiated by scandium, ytterbium and lanthanum triflates or a conventional BF3·MEA initiator was investigated. 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 time–temperature–transformation (TTT) diagrams. The improvement in the reworkable character of the materials prepared was confirmed by thermogravimetry. The thermomechanical characteristics were also evaluated.