T11 of anionic polystyrenes from zero shear melt viscosity

✍ Scribed by R.F. Boyer

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 854 KB
• Volume: 17
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(81)90107-5

✦ Synopsis

Abstrac~Zero shear melt viscosity data, r/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 Mn fall on three straight lines when plotted as log r/0 vs IO00/T, usually connected by curvature, with intersections corresponding to the liquid-liquid intermolecular transition, Tn, and an intramolecular liquid liquid transition, T'n, lying about 40 K above Tn. Tn and T' n are given in tabular and graphical form as a function of Mn. We conclude that zero shear conditions were attained and that quasi-equilibrium values of TH and T'u have resulted. Analysis of a third body of q0 data on anionic PS's by Suzuki reveals additional evidence for Tn. These new results on 71~ and T'n are discussed in terms of other literature data on melt viscosity of PS by other techniques for analysing such data.

1. Closeness to Tg at the low temperature end. 2. Closeness to T' H at the high temperature end. 3. Crossing a transition zone near the 160-170°C, with a sharp change in activation energy.