Thermosetting polymers from epoxy resin and a Nickel catalyst of diethylenetriamine

The kinetics and mechanism of cure reaction of DGEBA using a chelate of Ni(II) with diethylenetriamine (dien), Ni(dien)(2)I-2,I- as a curing agent was studied by DSC. TG curve of the complex curing agent showed mass loss in two region of temperature: 200-320 and 450-550 A degrees C. Dynamic DSC measurements showed only one exothermic peak with a maximum about 250 A degrees C depending on the heating rate. According to the methods of KAS and Ozawa-Flynn-Wall the values of E (a) were 92.5 and 96.2 kJ/mol, respectively. The isoconversional kinetic analysis in whole range of conversion, alpha = 0.02-0.95, showed small changes in the E (a) values in the region of alpha = 0.04-0.6 and most likely represent some average values (E (a) = 110 kJ/mol) between the values of E (a) of non-autocatalyzed and autocatalyzed reactions. Using the sole dependence of E (a) on alpha, the time required to reach fully cured materials under isothermal conditions were also predicted and compared with the experimental results.