Miscible ternary blends containing polycarbonate, SAN, and aliphatic polyesters

Abstract

Abstract Ternary blends comprising polycarbonate, (PC), poly(styrene‐co‐acrylonitrile) (SAN), and a polyester, either poly(1,4‐butylene adipate) (PBA), poly(1,4‐cyclohexanedimethylene succinate) (PCDS), or poly(ε‐caprolactone) (PCL), were found to be miscible based on the presence of a single glass transition temperature at many compositions. For all systems, the addition of just 1% by weight polyester resulted in a miscible blend for SAN/PC ratios of 1/1 and 3/1, and a region of immiscibility was generally observed for PC‐rich compositions with low polyester content. The melting point depression of PCL in the ternary and in binary mixtures was studied to obtain interaction parameters for the PCL/PC, PCL/SAN, and SAN/PC binaries. These parameters were used to calculate the locus of compositions which mark the boundary between single‐ and multiple‐phase behavior. Agreement between the calculated and experimental boundary was only fair. PCDS was found to be the most efficient of the three polyesters studied for solubilizing PC and SAN. SAN copolymer containing 25% acrylonitrile (AN), was found to be more easily solubilized in PC by PCDS than SAN containing 13% AN.