The effect of pressure on viscosity is an important but often overlooked aspect of the flow properties of polymeric materials. Generally, an exponential dependence (the so-called Barus equation: ?=?0exp(?P)) can be adopted to describe this effect. In this work two polymers (an atactic and a syndiotactic Polystyrene) were characterized as far as the effect of pressure on viscosity is concerned by analyzing the non-linearities in the so-called Bagley plots. The results obtained show that for both materials the average value of ? is in the range 1-3×10-8Pa -1. No relevant effects of temperature and shear rate were detected in the range analyzed. The data obtained were also described by means of a Cross-Vogel model, which reproduces the main features of experimental data.
Pressure effect on viscosity for atactic and syndiotactic polystyrene
Sorrentino A
2005
Abstract
The effect of pressure on viscosity is an important but often overlooked aspect of the flow properties of polymeric materials. Generally, an exponential dependence (the so-called Barus equation: ?=?0exp(?P)) can be adopted to describe this effect. In this work two polymers (an atactic and a syndiotactic Polystyrene) were characterized as far as the effect of pressure on viscosity is concerned by analyzing the non-linearities in the so-called Bagley plots. The results obtained show that for both materials the average value of ? is in the range 1-3×10-8Pa -1. No relevant effects of temperature and shear rate were detected in the range analyzed. The data obtained were also described by means of a Cross-Vogel model, which reproduces the main features of experimental data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
