CHARACTERIZATION OF ALKYD BASED THERMOSETTING RESINS - CALORIMETRIC INVESTIGATIONS

The rate of cure of different oxidative drying oil modified alkyd resi ns are investigated by DSC, when the cure is made under UV light or no t. We determine, from the Kissinger equation, the apparent activation energy at different stages of the curing process. This activation ener gy depends on the curing conditions (temperature, illumination or not) . These variations lead to the determination of a time constant, chara cteristic of the curing kinetics. Two particular values of the apparen t activation energy are also defined. The first one called Delta E(o) is a characteristic of the varnish at the liquid state, the second one called Delta E(inf) characterizes the stability of the structural sta te of the final film.