THERMOTROPIC LIQUID-CRYSTALLINE POLY(L-GLUTAMATE) ESTERS WITH LONG ALKYL CHAIN CONTAINING AROMATIC SEGMENT AT TERMINAL POSITION

Poly(L‐glutamate) esters (3a–3d) with long alkyl side chains containing a mesogenic aromatic segment at the terminal position were synthesized. The superstructure of these polypeptides in solution and film were found to hold a α‐helical conformation which was confirmed by CD, IR, and dichroic IR spectroscopy. The thermotropic liquid crystalline behavior was investigated by DSC, x‐ray diffraction, and polarizing microscopy with hot stage. Polymers 3a and 3b, having transesterification over 60%, were assumed at least to have two liquid crystalline states. Polymer 3c‐H‐95 exhibited one crystalline state and two liquid crystalline states; however, 3d‐H‐97 did not show distinct liquid crystalline states. Copyright © 1990 John Wiley & Sons, Inc.