Determination of the intrinsic viscosity of high-molecular-mass and ultrahigh-molecular-mass polymers

It was established that, in the concentration range accessible for viscomet ry, the efflux time of a polymer solution is a linear function of the polym er concentration. This is consistent with the Einstein-Simh equation. In th e general case, the efflux time of a solution with a polymer concentration tending to zero tau (e) does not coincide with the efflux time of the pure solvent tau (0). When the efflux time of a polymer solution is reduced by t au (e) rather than by tau (0) (as is done in the standard method), the redu ced viscosity becomes independent of the polymer concentration and equal to the intrinsic viscosity. The advantages of the proposed method arc especia lly important for the determination of the intrinsic viscosity of ultrahigh -molecular-mass polymers.