Phase equilibria of rodlike molecules in binary solvent systems

✍ Scribed by Akio Nakajima; Toshio Hayashi; Minako Ohmori

• Publisher: Wiley (John Wiley & Sons)
• Year: 1968
• Tongue: English
• Weight: 408 KB
• Volume: 6
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1968.360060708

✦ Synopsis

Phase relationships in solutions of rodlike molecules were invest.igat,ed wit>h solutions of poly(y-benzyl L-glutamate) having degrees of polymerization of 1550 and 3600, in N,N'dimethylformamide-methanol and in N,N'-dimethylformamidewater at 30°C. With these systems, corresponding boundary curves for isotropic and anisotropic solution were obtained as a fiinct,ion of composit.ion. Phase diagrams for these ternary systems were analysed on t,he basis of a theoretical treat,ment, by Flory for a binary system consisting of a rodlike polymer and a solvent, and found to be in good agreement. with that. predict,& theoretically. For example, t.he polymer concentration above which the isotropic phase cannot, exist and t,hat, of anisot,ropic conjugate phase agree with the values calculated. Fruthermore, viscosities were measured as a funct,ion of polymer concentration by the falling-sphere method to confirm the boundary composition between the isotropic solution and heterogeneous region. These results were also forind t.o coincide wit,h those on phase equilibrium.