T11 of anionic polystyrenes from zero shear melt viscosity

Abstract

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 M 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, T 1 and an intramolecular liquid-liquid transition, T 11 lying about 40 K above T 11 T 11 and T′ 11, are given in tabular and graphical form as a function of M n We conclude that zero shear conditions were attained and that quasi-equilibrium values of T 11 and T′ 11, have resulted. Analysis of a third body of n o data on anionic PS's by Suzuki reveals additional evidence for T 11. These new results on T 11 and T′ 11 are discussed in terms of other literature data on melt viscosity of PS by other techniques for analysing such data.