DIELECTRIC MEASUREMENTS OF POLY(GAMMA-ALKYL L-GLUTAMATE)S IN THE SOLID-STATE AS A CHECK OF APPLICABILITY OF THE 2 PHASE MODEL

Molecular motions of the following series of poly(γ-alkyl L-glutamate)s (PALG)s in the solid state were studied by the method of dielectric measurements; poly(γ-methyl L-glutamate), poly(γ-ethyl L-glutamate), poly(γ-propyl L-glutamate), poly(γ-butyl L-glutamate), poly(γ-amyl L-glutamate), and poly (γ-hexyl L-glutamate). Each sample exhibits a dispersion near 0°C due to sidechain motions. The time–temperature superposition principle was applicable for obtaining the master curve for all samples. The shift factor was well represented by the WLF-equation. The dispersion temperatures of PALG were found to monotonously decrease with increase in the number of carbons in the side-chain alkyl group. Kirkwood’s sech-law was applied to obtain the parameter α, which represents the degree of the breadth of the distribution of the relaxation time. It was found that the distribution of the relaxation time broadens with the increase in the number of carbons in the side-chain alkyl group. These results are discussed in terms of a two phase model in which the rigid α-helical backbone chain is embedded in the flexible side chain. © 1979, The Society of Polymer Science, Japan. All rights reserved.