Melt rheology of blends of semicrystalline polymers. I. Degradation and viscosity of poly(ethylene terephthalate)–polyamide-6,6 mixtures

Melt rheology of poly(ethylene terephthalate)–polyamide-6,6, and their blends was studied between 240°C and 300°C, in capillary and rotational rheometers. The flow curves were determined in the range of rate shear from about 10−2to 105 (s−1). The results indicate a considerable degree of compatibility, presence of associations between the two types of macromolecules, and cocrystallization. A new mechanism of flow for the blends has been proposed. The study also considers the kinetics of thermal degradation.