Surfactant bound polypeptides II. Liquid-crystalline behaviour of triton X-100 bound poly-γ-benzyl-l-glutamate

Abstract

The liquid-crystalline behaviour of two polymers in which the non-ionic surfactant Triton X-100 was bound covalently to low molecular weight poly-γ-benzyl-l-glutamate (degree of polymerization 21 (TRG-I) and 26 (TRG-II)) was studied in five non-aqueous solvents. Cholesteric mesophases were observed, significantly, at as low a concentration as 5–8 per cent (w/v) in chloroform, dimethylformamide, dioxane and dichloromethane. The cholesteric pitch, however, is small (e.g. 1.1 μm in a 10 per cent (w/v) solution in dichloromethane). The polymer TRG-II exhibited cholesteric mesophases in the mixed solvent dioxane: dichloromethane (2: 8 v/v) unlike the homopolymer poly-γ-benzyl-l-glutamate. Interestingly, in benzene solutions neat crystalline plates were formed.