Rheology and Phase Behavior of the System PBZT-Phosphoric Acid-Water

摘要

Our assignment was to map out the viscosity of PBZT in a suitable solvent as afunction of temperature, concentration, and shear rate. The most common solvent is polyphosphoric acid used also in synthesis, characterization, and processing. This solvent, as our studies have shown, is itself a complex system of polyphosphoric acids of different degrees of polycondensation and water in equilibrium, itself affected by temperature. In fact, in the polycondensation degrees used in the processing of PBZT, it is a mixture of orthophosphoric acid (OPA) and diphosphoric acid (DPA). This, with PBZT as a solute, gives rise to a complex phase diagram involving a variety of phases as previously investigated.