کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1785781 1023394 2015 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Relaxation dynamics and fragility during liquid-glass transitions of poly(propylene glycol)s
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Relaxation dynamics and fragility during liquid-glass transitions of poly(propylene glycol)s
چکیده انگلیسی
The acoustic and thermal properties of the liquid-glass transitions of propylene glycol and its oligomers, poly (propylene glycol)s, were studied by temperature modulated DSC and Brillouin scattering. The fragility indices were determined from Angell plots using the observed modulation frequency dependence of the complex heat capacity. The variation in the glass transition temperatures is discussed on the basis of the free volume theory. The relaxation time of the structural relaxation obeys the Vogel-Fulcher law, and its high frequency end is in good agreement with the result of the dielectric measurement in the literature. The correlation between the observed thermal expansion coefficients and the glass transition temperature is discussed based on the free volume theory. The sound velocity and attenuation were accurately determined as a function of the temperature by Brillouin scattering by combination with the refractive index measurement. The relaxation dynamics were discussed by considering the relaxation from segmental motions. All of these physical properties were discussed based on the third-order anharmonicity and the Grüneisen parameter.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Current Applied Physics - Volume 15, Issue 7, July 2015, Pages 805-810
نویسندگان
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