| Abstract |
The slow molecular mobility in high-cis poly (1,4-isoprene) has been studied by the dielectric technique of thermally stimulated currents. Three different kinds of motional processes have been identified: the Johari-Goldstein relaxation, the main or alpha-process and a mobility appearing above T-g that has been ascribed to the normal mode process. The temperature location of these relaxations was respectively at -85 to -80 degrees C, at -73 degrees C and at -65 degrees C. The fragility or steepness index was found to be m(alpha)= 60 and m(n) = 37, respectively for the alpha and the normal mode processes, in excellent agreement with the results obtained by dielectric relaxation spectroscopy (DRS). (C) 2015 Elsevier Ltd. All rights reserved. |
