HYDROGEN-BONDING IN POLYMER SYSTEMS INVOLVING POLY(P-VINYLPHENOL) .2. TERNARY BLENDS WITH POLY(ETHYL METHACRYLATE) AND POLY(METHYL METHACRYLATE)

An association model extended to ternary systems has been applied to poly(ethyl methacrylate) (PEMA)/poly(methyl methacrylate) (PMMA)/poly(p-vinylphenol) (PVPh) blends. In this ternary blend, PVPh is miscible with PMMA and PEMA, while the last two polymers are immiscible with each other. Using model parameters previously determined for binary PMMA/PVPh and PEMA/PVPh blends, the spinodal curve of the ternary system at 165 degrees C has been predicted and found to be very sensitive to the values of the solubility parameters employed. Fourier transform infrared (FTIR) measurements were conducted in order to obtain an indication of the miscibility boundaries in the ternary diagram. By comparing the experimental fraction of hydrogen-bonded carbonyl groups corresponding exclusively to PMMA and that of PEMA to the theoretical ones from the model, ternary PEMA/PMMA/PVPh compositions where phase separation has taken place can be identified. Several limitations of this approach for the ternary system have been pointed out.