On the infrared spectroscopic determination of self- and interassociation equilibrium constants used in the prediction of the phase behavior of hydrogen bonded polymer blends

We have previously shown that if chain connectivity effects are taken into account equilibrium constants determined from appropriate low molar mass mi xtures can be used to predict the phase behavior of analogous hydrogen bond ed polymer blends. Infrared spectroscopy has been classically used to deter mine appropriate self- and interassociation equilibrium constant values, bu t the particular methodology used has to be carefully considered on a case by case basis. Here we report on and compare the results of studies of very dilute cyclohexane solutions of 4-ethylphenol, ethyl isobutyrate, and dibe nzyl ether, in both the hydroxyl and carbonyl stretching region of the infr ared spectrum.