The curing reaction of an epoxy system consisting of a diglycidyl ether of bisphenol A (BADGE, n ¼ 0) and isophoronediamine (IPD), was studied by Fourier transform infrared spectroscopy (FTIR). The degree of conversions and the reaction rates at different isothermal curing temperatures were calculated from the infrared spectra using a method derived from Beer's law. This method is based on the ratio of the height of the characteristic absorbance peak to reference absorbance peak. A kinetic model proposed by Sourour and Kamal has been used to fit experimental data.
The curing reaction of a system consisting of a diglycidyl ether of bisphenol-A (n 5 0) and hemin (a protoporphyrin IX containing an iron ion and an additional chloride ligand) was studied with a differential scanning calorimeter. A maximum value of 2488.3 6 8.4 J g 21 was obtained for the enthalpy of the reaction. The kinetics of the process was studied by the isothermal method, observing that it obeys to Kamal's model, with an overall reaction order equal to 3. From the dependence of the kinetic constant with temperature, the activation energy, activation enthalpy, and activation entropy were determined. The ratio of the kinetic constants associated to the autocatalytic and nth order terms of the reaction rate, together with the thermodynamic activation parameters suggest a trend to the autocatalytic path mechanism with increasing temperatures. This study demonstrates that macrocycles can be used as cross-linking agents for curing epoxy resins and that when metallomacrocycles are used, metal ions can be introduced into the network structure.
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