THE PHASE-BEHAVIOR OF TERNARY BLENDS CONTAINING POLYCARBONATE, PHENOXY, AND POLYCAPROLACTONE

Ternary blends comprising bisphenol-A polycarbonate (PC), the polyhydroxyether of bisphenol-A (Phenoxy), and poly( epsilon -caprolactone) (PCL) were found to be generally miscible at PCL levels greater than 60% by weight and to show multiple amorphous phases at lower PCL levels. The melting point depression of PCL in the miscible region of the ternary and in the miscible binary blends with PC and Phenoxy was examined to obtain the enthalpic interaction parameters, B//i//j, for each of the three binary interactions. The interaction parameters were used to calculate the locus of compositions for which the heat of mixing is zero. The locus was found to agree well with the observed boundary between miscible and multiphase behavior in the ternary.