Effect of some selective aromatic cosolutes on the main thermodynamic parameters of aqueous poly(N-vinyl-2-pyrrolidone) solutions

Kavlak S., Guner A.

JOURNAL OF APPLIED POLYMER SCIENCE, vol.78, no.3, pp.507-510, 2000 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 78 Issue: 3
  • Publication Date: 2000
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.507-510
  • Hacettepe University Affiliated: No


Cloud-point curves and theta temperatures have been determined for aqueous solutions of poly(N-vinyl-2-pyrrolidone) at several concentrations for a variety of aromatic additives (benzoic acid, o- and p-hydroxy benzoic acid, aniline, o- and p-hydroxy aniline). The theta temperature of polymer is suppressed at lower temperatures depending on the chemical structure and the concentration of additives. The effectiveness, in decreasing order, of the cosolutes in reducing the temperature is: p-hydroxy benzoic acid > o-hydroxy benzoic acid > p-hydroxy aniline > o-hydroxy aniline approximate to benzoic acid > aniline. It is understood that changes in theta temperatures caused by the cosolute result from the changes taking place in the hydrophilic and hydrophobic interactions among polymer, solvent and polymer-solvent interactions from the added cosolute. (C) 2000 John Wiley & Sons, Inc.