Simple Mathematical Approach for Determining the Compositions of the Different Phases Resulting From the Phase Separation Behavior of Polymer Blends

In this article, the Flory–Huggins theory is utilized to formulate two essential equations for determining the compositions of the different phases resulting from the phase separation behavior of polymer blends. The equations use a graphical approach to determine the numerical outcomes of the compositions of the different phases, serving as a universally applicable illustration. The results show that when the Flory–Huggins interaction parameter is less than the critical value, the graphs of the equations have no intersection point, indicating the absence of phase separation. Conversely, when the Flory–Huggins interaction parameter equals the critical value, the graphs of the equations display a single intersection point. Furthermore, if the parameter value exceeds the critical value, the graphs of the equations show two symmetrical intersection points, indicating that phase separation can occur. The present study also includes a discussion on the correlations between the compositions of the different phases and the Flory–Huggins interaction parameter.