Continuity of solvent quality in polymer solutions. Poor-solvent to Θ-solvent continuity in some polystyrene solutions

✍ Scribed by Attila Imre; W. Alexander Van Hook

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 277 KB
• Volume: 35
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199706)35:8<1251::aid-polb11>3.0.co;2-7

✦ Synopsis

Critical temperatures for polystyrene/methyl acetate (PS/MA) and polystyrene/ethyl formate (PS/EF) solutions were measured at positive (PS/MA, PS/EF) and negative (PS/MA) pressure. The results confirm that solvent quality is sensitive to pressure; some solvents, designated Q, at P nominal Ç 0, undergo a Q-to-poor transition at negative pressure, and others, nominally designated ''poor,'' show a poor-to-Q transition at positive pressure. Thus, any dichotomous division into sets of ''poor'' and ''Q'' solvents is inaccurate, unless it accounts for the effects of pressure and other variables on solvent quality.