T11 of anionic polystyrenes from zero shear melt viscosity

Zero shear melt viscosity data, n_o, as a function of temperature on anionic polystyrenes (PS), as measured by Pierson and by Ueno et al., have been analysed using both a first derivative program and computerized regression analysis. Such data at each $\text{M}{}_{\mathrm{n}}$ fall on three straight lines when plotted as log n_o vs 1000/T, usually connected by curvature, with intersections corresponding to the liquid-liquid intermolecular transition, T₁ and an intramolecular liquid-liquid transition, T₁₁ lying about 40 K above T₁₁T₁₁ and T′₁₁, are given in tabular and graphical form as a function of $\text{M}{}_{\mathrm{n}}$ We conclude that zero shear conditions were attained and that quasi-equilibrium values of T₁₁ and T′₁₁, have resulted. Analysis of a third body of n_o data on anionic PS's by Suzuki reveals additional evidence for T₁₁. These new results on T₁₁ and T′₁₁ are discussed in terms of other literature data on melt viscosity of PS by other techniques for analysing such data.