کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5186234 | 1381098 | 2006 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Physical nature of complex structural relaxation in polysiloxane - PMpTS: α and αⲠrelaxations
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Structural relaxation processes in poly(methyl-para-tolyl-siloxane) (PMpTS) polymers of three molecular weights were studied using dynamic light scattering. Two relaxation processes: the usual α and an additional slow one αⲠwere observed and studied as function of temperature and molecular weight. Contrary to the structural relaxation, we find that in a plot T-Tg the relaxation times for the αⲠprocess for all molecular weights do not collapse to a single curve. For one of the samples the light scattering correlation functions were compared with the corresponding functions obtained by means of mechanical relaxation, dielectric spectroscopy and computer simulations. The simulations show that the bimodal distribution, i.e. the α relaxation and the slow (αâ²) process are contained in the correlation functions of most of the probes (optical anisotropy, dipole moment, chain bond, density) in agreement with experimental observations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 47, Issue 20, 20 September 2006, Pages 7231-7240
Journal: Polymer - Volume 47, Issue 20, 20 September 2006, Pages 7231-7240
نویسندگان
A. Patkowski, J. Gapinski, T. Pakula, G. Meier,