Intrinsic viscosity of PVP polymers in extremely diluted solutions

Abstract In conventional viscometry studies an additional treatment of data is necessary in order to obtain the expected linear dependence of the reduced viscosity on concentration in extremely diluted polymer solutions. This work reports on the direct measurements of this dependence using a new Couette-type viscometer. The values of intrinsic viscosity and Huggins coefficient of the studied poly(N-vinyl-2-pyrrolidone) (PVP) water solution notably differ from the previous results obtained by the traditional capillary viscometers. From the obtained data the parameters used in the bead-spring theories of polymer universal behavior, such as the gyration radius and the longest relaxation time are calculated.