Polymer Bland에서의 상평형에 관한 연구

Study on the Phase Diagram for the Polymer Bland

We study on the phase diagram of the polymer blend. For this purpose, one PS (polystyrene) and two PI(polyisoprene) were employed whose molecular weights were low enough to make the experimental determinations possible. The weight-average molecular weight(Mw) of PS was 2514, and Mws of two PIs were 2700. Interaction energy density (IED) of the Flory-Huggins lattice theory was defined as a function of temperature and composition, and the consequent equations for the binodal, and critical points were derived. By fitting the experimental binodal points to the derived binodal curve with a nonlinear regression method, the expression for the IED was determined. And the expression for the IED obtained from this study was compared with those reported in the literatures. Also were discussed the importance of accuracy in the expression the IED, and the IED's dependency on the temperature, composition and molecular weights.