Glass transition temperature-temperature-property (TgTP) diagram for EPY® epoxy system

Evolution of storage and loss moduli during conversion progress of the filled epoxy system EPY (R) (Epidian 6 with triethylenetetramine), applied for the production of machine foundation chocks, was studied using dynamic mechanical thermal analysis (DMTA). The results obtained and the results previously reached by differential scanning calorimetry (DSC) and rotational viscometry made possible to determine the diagram glass transition temperature-temperature-property (TgTP) for the investigated system, where T-g is the direct measure of conversion and P denotes property under investigation - loss modulus. This way of using T-g in this diagram makes possible the linearization of the relationships among the temperatures corresponding to the maxima and minima of the physical properties and the extent of cure. The lines within TgTP diagram show the courses of structural transformations during cure i.e. glass transition (T-g), beta-transition (T beta) and gelation (T-gel(g)). The diagram lines separate several regions which are dependent on the extent of cure and the material shows different physical properties within each of them. TgTP diagram calculated for the EPY (R) material can facilitate understanding of the relationships among transitions and material properties.