Study of mechanical and rheological behaviors of linear and branched polycarbonates blends

A study of the mechanical and rheological properties of linear and branched polycarbonates blends is presented. Phase separations of the blends were c hecked through DSC and SEM, and, subsequently, mechanical and rheological p roperties were investigated. Phase separations were not observed in the ble nds. The mechanical properties were examined through tensile, flexural, and impact tests. All the mechanical properties of the blends were relatively independent of the compositions. For study of the rheological properties, m elt viscosity, storage and loss moduli, and melt tension of the blends with various compositions were examined at various temperatures. The dependence of the viscosity on the molecular weight was also studied. As the content of branched polycarbonate increases, the dependence of the viscosity on the molecular weight and the shear thinning behavior became more marked. Melt tensions were also increased as the branched polycarbonate content increase d in the blends for all tested temperatures. In this study, the blend syste ms which have same mechanical properties but different rheological properti es can be obtained through blending of linear and branched polycarbonates. (C) 2001 John Wiley & Sons, Inc.