Phase behaviour of poly-(λ-benzyl-L-glutamate) in benzyl alcohol

Polarized optical microscopy has been used to investigate phase transitions in the poly-(λ-benzyl-L-glutamate) benzyl alcohol system and these have been compared with the predictions of Flory. All of the samples studied form gels at room temperature. The behaviour of the lowest concentration studied, 5 per cent by volume, shows transitions in the optical microscope compatible with the Flory phase diagram, becoming isotropic at elevated temperatures. Gels of higher concentrations exhibit bulk phase separation into an isotropic liquid phase and an anisotropic phase at room temperature, also in accord with the Flory predictions; the texture of the anisotropic phase varies with concentration. At higher temperatures these concentrations exhibit two coexistent anisotropic phases.