کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5188850 1381170 2008 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Lindemann-like size-independent glass-transition criterion for polymers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Lindemann-like size-independent glass-transition criterion for polymers
چکیده انگلیسی

It is well known that the intrinsic melting mechanism is independent of crystal size according to Lindemann's melting criterion. In order to probe whether the glass transition mechanism is also size-independent, segment dynamics of free-standing polystyrene (PS) films is determined by considering the temperature- and thickness-dependent number of styrene segments Nα(T,D) in the cooperative rearranging region (CRR). Under the help of Adams-Gibbs glass transition theory and molecular dynamics simulation, Nα(T,D) function is established and it decreases as D decreases or T increases. However, Nα[Tg(D),D] at the glass transition temperature Tg(D) is size-independent, which is consistent with the simulation results obtained by Donth's method. Meanwhile, its relative temperature function Nα{[T − Tg(D)]/Tg(D)} is also size-independent. Therefore, Nα[Tg(D),D] function as a criterion for glass transition, which describes the physical nature of the glass transition, is similar to the vibrational amplitude in Lindemann's melting criterion.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 49, Issue 16, 28 July 2008, Pages 3578-3581
نویسندگان
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