Reliability of Intrinsic Viscosity Estimated by Single Point Procedure at High Concentrations

抄録

A simple calculation method to evaluate intrinsic viscosity from viscosity data at a finite concentration (i.e. without the extrapolation to zero concentration) is examined to clarify its applicability. The method, [η] = {2(η_sp-lnη_r)}^1/2/c, is based on Huggins and Fuoss-Mead plots. Here, η_sp and η_r are respectively specific viscosity and relative viscosity, and c is concentration. Its applicability was tested with published viscosity data for polystyrene and poly(α-methyl styrene) solutions. The method was found to work well for good solvents in the concentration regime c / c * ≤ 2, where c * is the overlapping concentration. On the other hand, for the case of θ solvents, the applicability of the method was very limited to low concentration of c / c * ＜ 0.4, due to the viscosity enhancement by the entanglements.