Abstract
Steadyshear and oscillatory shear rheological measurements were performed to characterize the solution rheological behavior of poly(3,3′-diaminodiphenylsulfone terephthaloylchloride) (P(3,3′-DDS-TPC)) in dimethyl sulfoxide (DMSO). The effects of temperature, concentration, and weight-average molar mass () on the rheological properties were investigated. From the temperature dependence of zero-shear viscosity, the flow activation energies, Eη, of P(3,3′-DDS-TPC)/DMSO solutions were calculated. Both the overlap concentration, C*, and the entanglement concentration, Ce, were determined from the concentration dependence of the specific viscosity ηsp. All the P(3,3′-DDS-TPC) solutions, we studied, can be separated into three regimes: the dilute, semidilute-unentangled, and entangled regime with slopes of 1, 1.3, and 3.9, of concentration versus ηsp plots, respectively, which are consistent with scaling predictions for flexible polymers in a good solvent.
Acknowledgments
This work was financially supported by Shanghai Science and Technology Commission (09JC1400800) and National Natural Science Foundation of China (11079015).