Abstract

The solutions of polyvinylidene fluoride (PVDF) in dimethyl acetamide (DMAc) were rheologically investigated. In the dilute concentration regime, the solutions gave values of Huggins constant lower than 0.52, which decreased with increasing temperature. This suggests that DMAc is a good solvent and the solvating power is increased with increasing temperature. The solutions exhibited an inflection point on the log-log plot of $\eta_{sp}$ versus $(\eta)C$. Further, the slope was slightly decreased with increasing temperature from 10 to $30^{\circ}C$. At high concentrations, the solutions did not show lower Newtonian flow region. Further, raising temperature from 10 to $30^{\circ}C$ increased viscosity and yield stress of the solutions. Increasing concentration had the same effect on the rheological properties as increasing temperature. Relaxation time $(\lambda) $ increased as the concentration and temperature increased.

주제어

#polyvinylidene fluoride   #dimethyl acetamide   #solution   #Huggins constant   #rheology   #yield stress  

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