THE EFFECT OF HYDROGEN-BONDING ON THE PHASE-BEHAVIOR OF TERNARY POLYMER BLENDS

In this paper theoretical and experimental studies of the phase behavi our of ternary polymer blends are reviewed. Particular emphasis is pla ced upon the effect of specific interactions (hydrogen bonds). The ass ociation model developed to predict the phase behaviour of binary hydr ogen-bonded polymer blends has been extended to ternary polymer blends . Simulations have been performed to illustrate the major effects of ' physical' (primarily dispersion) and 'chemical' (hydrogen bonding) for ces on phase behaviour. Theoretically predicted phase diagrams have al so been compared to experimental results obtained from five hydrogen-b onded ternary polymer blend systems. Overall, the agreement is satisfa ctory. One general conclusion is that it will be very difficult to fin d ternary polymer blends that exist in a single phase over a wide comp osition range. Furthermore, in most cases an immiscible binary blend c annot be made homogeneous by introducing a small amount of a third pol ymer ('compatibilizer').