CONFORMATION AND MOLECULAR-MOTION OF POLY(L-GLUTAMATE) WITH LONG N-ALKYL SIDE-CHAINS IN THE SOLID-STATE AND THE LIQUID-CRYSTALLINE STATE AS STUDIED BY HIGH-RESOLUTION C-13 NMR-SPECTROSCOPY

C-13 CP-MAS NMR experiments are carried out for poly(gamma-n-octadecyl-L-glutamate) over a wide range of temperatures, in order to elucidate exact dynamic and conformational features in the solid state and the liquid crystalline state, as well as from the experimental findings reported previously by C-13 CP-MAS NMR and H-1 pulsed NMR methods. From these experimental results, it was found that at low temperatures n-alkyl side chains take an all-trans zigzag conformation, above 40-degrees-C they behave like liquid alkanes in a mobile state, and in the temperature range 0-20-degrees-C they are in a phase similar to the rotator phase of n-alkanes. The main chain takes on a right-handed alpha-helix conformation within the temperature range -40-230-degrees-C. Further, it was found that at temperatures above 40-degrees-C the polymer forms several liquid crystalline phases, in which the molecular motions of the polymer are different from each other.