کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9778112 1510571 2005 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Relaxations in polystyrene below the glass transition studied by internal friction measurement
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Relaxations in polystyrene below the glass transition studied by internal friction measurement
چکیده انگلیسی
The results of internal friction (IF) measurement for polystyrene made over a wide frequency range of 0.001-10 Hz and in a temperature range of 11-74 °C were analyzed. At lower frequencies and higher temperatures, IF increases when the frequency is decreased, and the increase is larger for higher temperatures; IF increases when the temperature is increased, and the increase is larger for lower frequencies. These behaviors were explained by the viscosity relaxation based on the Maxwell model causing IF inversely proportional to frequency and viscosity. The relaxation time was experimentally determined as functions of temperature and frequency. The observed relaxation time could be represented as τ = τ0exp(E/kBT) (thermal activation); a combination of two relaxations was seen (double relaxation); τ0 and E were dependent on the frequency; log τ0 linearly decreased with increasing E (compensation effect). The relaxing elements were considered to jump cooperatively, and the element could be a part of molecular chains in the material. The results of the present study were compared with those obtained from our previous viscosity experiment.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 351, Issues 14–15, 15 May 2005, Pages 1300-1306
نویسندگان
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