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ABSTRACT:The polymerization kinetics of the reaction between diglycidylether of bisphenol A (DGEBA) and ethylenediamine (EDA) was analyzed, using dynamic scanning calorimetry, in both isothermal and programmed heating-rate modes. A simple mechanistic model, consisting of an equilibrium reaction generating an epoxy-hydroxyl complex, and including two possible mechanisms for the consumption of amine hydrogens [(1) with free epoxy groups, (2) with the epoxy-hydroxyl complex], provided a reasonable fitting of the whole set of experimental results. It was found that the equilibrium constant decreased with temperature, making less important the reaction mechanism involving the epoxy-hydroxyl complex.

Partition and distribution constants of alkali-metal (lithium, sodium, potassium, rubidium) picrates in the waterÈbenzonitrile solvent system and ion-pair formation constants for these electrolytes in the water saturated organic phase at 298.15 K derived from distribution data are reported. Partition data are discussed with respect to transfer data for these electrolytes referred to the process involving the pure solvents. The extraction of alkali-metal picrates from water to benzonitrile by ethyl p-tert-butylcalix(4) arene tetraethanoate is investigated taking into account the extent of ion-pair formation of the alkali-metal complex salt in benzonitrile. A quantitative assessment of the individual processes which contribute to the overall extraction of alkali-metal picrates by the calixarene ester from water to benzonitrile is reported for the Ðrst time.