Rheology and viscosity master curve of poly(vinylidene fluoride) concentrated solution

Poly(vinylidene fluoride) solutions of different mass fraction were prepared by using DMSO as solvent and their rheological properties were investigated on a HAAKE RS150 cone-and-plate rheological machine.The flow curves of different PVDF mass fraction,the dependence of zero shear viscosity on PVDF mass fraction and the viscosity master curves were studied.The result showed that under lower shear rate,the apparent viscosity decreases somewhat,and shows a characteristic shear rate γc.When the shear rate is bigger than γc,the apparent viscosity decreases sharply showing a strong dependence on shear rate.The equations of zero shear viscosity versus mass fraction are obtained from the relationship between the zero shear viscosity and mass fraction.The viscosity master curve shows that the slop of master curves is just the same as the calculation value acquired from Graessley theory.