Open AccessMeasuring and analyzing the cooling dielectric spectra of the -relaxation in dimethyl phthalate series materials
Author(s) -
Wei Lai,
Zhou Lan-Lan,
Guihua Liu,
Wen Zhang,
Zhang Wu-Zhi,
Shang Zhang,
Feng Yong-Hong,
Zhou Heng-Wei,
Zhang Jin-Lu,
Yineng Huang
Publication year - 2012
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.61.017701
Subject(s) - dimethyl phthalate , dielectric , relaxation (psychology) , materials science , phthalate , series (stratigraphy) , diethyl phthalate , spectral line , thermodynamics , molecule , nuclear magnetic resonance , analytical chemistry (journal) , organic chemistry , chemistry , physics , composite material , quantum mechanics , psychology , social psychology , paleontology , optoelectronics , biology
The cooling dielectric spectra of the -relaxation in dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and dioctyl phthalate series materials are measured, and the average relaxation time of the -relaxation a as a function of temperature T is obtained. By fitting the a data to the empirical Vogel-Fulcher-Tammann law a = 0 exp (A/(T-T0)), the values of 0, A and T0 of the series materials are obtained. The results of 0, A, T0 and Tg show some variation regularities with the carbon number n in the side-group of dimethyl phthalate series molecules. And specifically, with the increase of n, the internal degrees of freedoms of the molecules, A and Tg indicate almost the same tendencies, i.e. first coming down and then going up, while 1/0 and T0 have quite similar behaviors, i.e. first reducing rapidly and then keeping at near constant values.