کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5190654 | 1381213 | 2006 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Low frequency ac conduction and dielectric relaxation behavior of solution grown and uniaxially stretched poly(vinylidene fluoride) films
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The measurements of ac conductivity [Ïm(Ï)], dielectric constant [Éâ²(Ï)] and loss [Éâ³(Ï)] have been performed on solution grown (thickness â¼85 μm) and uniaxially stretched (thickness â¼25, 45 and 80 μm) films of poly(vinylidene fluoride) (PVDF) in the frequency range 0.1 kHz-10 MHz and in the temperature range 77-400 K. The Ïm(Ï) can be described by the relation Ï(Ï) = AÏs, where s is close to unity and decreases with increase in temperature. Three relaxations, observed in the present investigation, have been designated as the αc-, the αa- and the β-relaxations appearing from high temperature side to the low temperature side. The αc-relaxation could not be observed in the case of uniaxially stretched poly(vinylidene fluoride) films. The αc- and αa-relaxations are associated with the molecular motions in the crystalline regions and micro-Brownian motion in the amorphous regions of the main polymer chain, respectively, whereas the β-relaxation is attributed to the rotation of side group dipoles or to the local oscillations of the frozen main polymer chain.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 47, Issue 16, 26 July 2006, Pages 5919-5928
Journal: Polymer - Volume 47, Issue 16, 26 July 2006, Pages 5919-5928
نویسندگان
Ramadhar Singh, Jitendra Kumar, Rajiv K. Singh, Amarjeet Kaur, R.D.P. Sinha, N.P. Gupta,