Analysis of the equilibrium melting point depression to estimate polymer-polymer interaction parameter

Miscible polymer blends in wich one or more of the components are crystallizable are studied with considerable interest. This is at least partially due to the fact that roughly one-half to two-thirds of all commercially significant polymers are crystalline or crystallizable. For these systems, the most widely used technique for estimating the magnitude of the polymer-polymerinteraction parameter, ?12, is melting point depression. The intent of this paper is to present to the participants of the school a critical review of the theory and procedures used to calculate the interaction parameter from melting point data and to draw attention to the difficulties associated with deriving experimental and equilibrium melting data. Starting from the Flory-Huggins Theory it is revised the Kwei-Frisch approch, the application of the melting point depression to the Equation of State and finally some important aspects concerning the determination of the experimental point.