DIELECTRIC STUDIES ON SOLUTION OF COPOLY (ETHYL-L-ASPARTATE-BENZYL-L-ASPARTATE)

Abstract

A dielectric study on a solution of copoly(ethyl-L-aspartate-benzyl-L-aspartate)s with various compositions synthesized by ethylation of poly (β-benzyl-L-aspartate) was performed and dielectric constants were obtained as a function of temperature and frequency. A dielectric dispersion attributable to rotation of the α-helix was observed for all the copolyaspartates. Static dielectric constants were estimated by Cole-Cole plots and the dipole moment of the copolyaspartate was evaluated by the aid of the Barriol-Weissbecker and Applequist-Mahr equations. There was no abrupt change in the dipole moment at the transition point of the helix sense from the right- to left-handed α helix, indicative of the absence of both random coil conformation and an equimolar mixture of the rightand left-handed α helical residues in a chain at the transition point.