The non-Debye relaxation behavior of hyperbranched polyglycerol was investigated by broadband dielectric spectroscopy. A thorough study of the relaxations was carried out paying special attention to truncation effects on deconvolutions of overlapping processes. Hyperbranched polyglycerol exhibits two relaxations in the glassy state named in increasing order of frequency and processes. The study of the evolution of these two fast processes with temperature in the time retardation spectra shows that the absorption is swallowed by the in the glass-liquid transition, the absorption being the only relaxation that remains operative in the liquid state. In heating, a temperature is reached at which the absorption vanishes appearing the relaxation. Two characteristics of absorptions, decrease of the dielectric strength with increasing temperature and rather high activation energy, are displayed by the process. Williams’ ansatz seems to hold for these topologically complex macromolecules.
Secondary and primary relaxations in hyperbranched polyglycerol: A comparative study in the frequency and time domains
Abel Garcia-Bernabé, Gustavo Dominguez-Espinosa, Ricardo Diaz-Calleja, Evaristo Riande, Rainer Haag; Secondary and primary relaxations in hyperbranched polyglycerol: A comparative study in the frequency and time domains. J. Chem. Phys. 28 September 2007; 127 (12): 124904. https://doi.org/10.1063/1.2780153
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