Phase equilibria in the two-phase system polystyrene—liquid sulphur dioxide

✍ Scribed by Albihn, Per ;Kubát, Josef

• Book ID: 104527139
• Publisher: Wiley (John Wiley & Sons)
• Year: 1981
• Tongue: English
• Weight: 470 KB
• Volume: 13
• Category: Article
• ISSN: 0007-1641
• DOI: 10.1002/pi.4980130311

✦ Synopsis

Abstract

The concentration and molecular weight distribution (GPC) of polystyrene (PS) in the two phases of the PS‐SO~2~ (δ)‐system were determined. Typical concentrations of PS in the upper phase were around 30%, while the lower phase contained at most 1% PS. An exception was a PS‐grade with a low molecular weight (MW 3.5 · 10^3^), which dissolved homogeneously. The molecular weight of PS in the lower phase was substantially below an the one found in the concentrated phase. Mechanical agitation was necessary to attain an equilibrium state; during the equilibration the upper phase became more diluted. At the same time the molecular weight of the lower phase PS‐fraction increased, while the MW value in the upper phase remained practically unchanged and equal to that of the virgin sample. The fractionation with regard to the molecular weight between the two phases was also reflected in the __T__g‐values of the fractions. The value of X(Flory‐Huggins parameter) determined from vapour pressure data above the concentrated phase was 0.8–1.