Cationic copolymerization of cycloaliphatic epoxy resin with an spirobislactone with lanthanum triflate as initiator Kinetics of the curing process

3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (ECH) was cured with different proportions of 1,6-dioxaspiro[4,4]nonane-2,7-dione (s(gamma-BL)) using lanthanum triflate as a catalyst. DSC was used to obtain kinetic data associated to the curing process by means of series of non-isothermal experiments. Fourier transform infrared spectroscopy in attenuated total reflection mode (FT-IR/ATR) was used to study the evolution of the epoxide group in order to compare experimental isothermal data with simulated isothermal data. The complexity of the process itself enabled us to compare different procedures for obtaining isoconversional data and to determine the kinetic model that best describes the curing process. An increase in the proportion of s(gamma-BL) increases the speed of the curing process. By means of applying isoconversional methods to dynamic experimental data, we observed that an increase in the proportion of s(gamma-BL) leads to an overall decrease in the activation energy for the different formulations. Kinetic parameters that were determined using both differential and integral isoconversional procedures were compared. This allowed us to analyze and to discuss the usefulness of different methods in order to obtain a suitable kinetic triplet at each step of the curing of the ECH/s(gamma-BL) system using lanthanum triflate as a catalyst. (C) 2005 Elsevier B.V. All rights reserved.