Stability conditions of two-phase equilibria of quasi-binary systems consisting of multicomponent polymers dissolved in a single solvent

✍ Scribed by Kenji Kamide; Shigenobu Matsuda; Hironobu Shirataki

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 917 KB
• Volume: 27
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(91)90092-3

✦ Synopsis

An attempt has been made to derive theoretically the discriminant of criteria for the stability of critical solution point (CSP) for a quasi-binary system consisting of a multicomponent polymer and a single solvent, taking into consideration the concentration-and molar mass-dependences of the polymer-solvent interaction parameter X. Based on this equation, the stability of CSP on the calculated cloud point curve was judged and the effect of the polymolecularity of the polymer and the concentration dependence of ;~-parameter on the stability was examined. It was shown that, when Z is independent of the concentration, CSP is always stable for the polymer with Schulz-Zimm type molecular weight distribution, but CSP becomes unstable for the polymer with Wesslau type molar mass distribution and/or having a ratio of weight-to number-average degree of polymerization higher than about three. The stability of CSP of a solution consisting of double peak molar mass distribution polymer (mixture of two polydisperse polymer homologues) and a single solvent is also discussed.