کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1432103 | 987390 | 2005 | 7 صفحه PDF | دانلود رایگان |
Relaxation effects in the copolymers of dedecalactam with oligotetramethylene glycol have been investigated by a dielectric method. The dielectric constant and dielectric loss were determined in the frequency range 10 Hz-1 MHz over the temperature range 120–300°. The dodecalactam content was varied from 100 down to 19 mol%. Two relaxation regions were found: a high-temperature region (α) associated with segmental mobility (glass-transition) and a low-temperature one (β) relating to local mobility in the copolymers. The glass-transition temperatures were determined as well as the activation energies and the relaxation time distribution parameters, and the dipole moment of the polydodecalactam repeat-unit was calculated. The glass transition temperature and the dielectric relaxation intensity (increase in the dielectric constant) decrease linearly as the amount of polyester fragments increases.
Journal: Polymer Science U.S.S.R. - Volume 33, Issue 10, 1991, Pages 1999-2005