Formation of Anisotropic Phase of Low-molecular-weight Poly(γ-benzyl-l-glutamate)s in Solution

Abstract

Abstract Low-molecular-weight poly(γ-benzyl-l-glutamate)s having degrees of polymerization (D. P.) 4 and 8 give an anisotropic phase in ethylene dichloride, if the concentration is appropriately chosen and the solution is incubated at a suitable temperature range. The optimum condition of concentration and temperature is more restricted for D. P. 8 than for D. P. 4. Ethylene dibromide solutions of the D. P. 4 specimen also give an anisotropic phase at some conditions. Infrared spectra and x-ray diffraction together with polarized microscopic observations suggest that the anisotropic phase consists of the β-structure of antiparallel arrangement of extended polypeptide chains; it has regular sequences of chains in the main chain direction and a stack of β-sheets in the side chain direction.