THERMAL SCANNING RHEOMETER ANALYSIS OF CURING KINETIC OF AN EPOXY-RESIN - 2 - AN AMINE AS CURING AGENT

The curing reaction of the system diglycidyl ether of bisphenol A (DGE BA) with different amine concentrations (TETA) has been studied by mea ns of thermal scanning rheometer (TSR) and dynamic mechanical thermal analyser (DMTA). The aim of this work was focused on studying the effe ct of the amine concentration on the kinetic, the theologic characteri stics during the crosslinking process, and the dynamic-mechanical prop erties of the system. Through TSR measurements, the gel time was obser ved to vary with amine concentration and cure temperature when measure ments were carried out under isothermal conditions. The gel time also was found to depend on the heating rate when the measurements were don e varying the temperature. The apparent activation energy (Ea) of each system was calculated from two different methods; the gel time (tg) a nd the complex viscosity (eta) measurements, respectively. The study of the dynamic-mechanical properties of the resins such as epoxy by me ans of the three-point bending mode in DMTA, gives information of thei r viscoelastic properties allowing the calculation of the glass transi tion temperature (Tg) and the apparent activation energy of the relaxa tion process (Ea). (C) 1998 Elsevier Science Ltd. All rights reserved .