PECULIARITIES OF THE GLASS-TRANSITION TEMPERATURE OF BINARY POLYMERICSYSTEMS - ENTROPIC AND ENTHALPIC TREATMENTS

The concentration dependence of the glass transition temperature T(g) of binary polymeric systems, for the Couchman entropic and enthalpic t reatments, has been described by taking into account the temperature d ependence of the specific-heat increments DELTAc(p)(T) and the presenc e of a characteristic temperature T0. It is shown that at T0 the analy tical equations undergo a sudden change. Comparison of the equations o btained with a set of experimental data on the poly(vinyl chloride)-di butyl phthalate system appears to be satisfactory. The treatment allow s one to characterize a binary system with suitable thermodynamic para meters.