Investigação da cinética de cura por calorimetria diferencial exploratoṕ ria (DSC) de resinas epóxi preparadas a partir de óleo de soja epoxidado com diferentes anidridos e aminas terciárias

Abstract

In the present work, differential scanning calorimetry (DSC) was used to investigate the curing reaction kinetics of epoxy resins produced from reaction of epoxidized soybean oil (ESO) with cyclic anhydrides dodecenylsuccinic (DDS), maleic (MAL), phthalic (PA), succinic (SUC) and hexahydrophthalic (CH), in the presence of tertiary amines such as triethylamine (TEA), N,N-dimethylaniline (ARO) and 1,4-diazabicyclo[2,2,2]octane (DABCO). The heating rate, the nature and structure of anhydrides and amines were found to affect the curing reaction. The dynamic methods of Kissinger, Ozawa and Barrett were used to calculate the activation energy of the reactions where different anhydrides were used. DDS and maleic anhydrides were more reactive than the others. In studying the influence from the catalyst, we used the Barret's method to determine the activation energy of the reactions. The 1,4-diazabicyclo[2,2,2]octane amine (DABCO) was the most reactive, showing the lowest activation energy (Ea= 51 kJ.mol -1) and pre-exponential factor (In A0 = 9 s-1).