Kinetics of Formation of Heterocyclic Polymer Networks. 3. Catalyst Effect

Abstract

Non-isothermal trimerization kinetics of 1,6-hexamethylene diisocyanate (HMDI) in the reaction mixture with epoxy resin (ER) at a fixed ratio HMDI/ER = 85/15 (mass) catalyzed by differential concentrations of triethylene amine (TEA) was studied by differential calorimetry at four heating rates. In contrast to the simple single-step models, the isoconversional approach proved to describe quantitatively the reaction kinetics over the entire range of conversions, The apparent activation energies of the curing process and the corresponding pre-exponential factors tended to decrease smoothly, the higher the conversion, whereas a definite excess of the amine component turned out to be necessary to arrive at the maximum reaction rate.