کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
675267 | 1459611 | 2008 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Modulated calorimetry of poly(1,4-oxybenzoate), poly(2,6-oxynaphthoate), and their copolymers
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Poly(1,4-oxybenzoate) (POB) and poly(2,6-oxynaphthoate) (PON) and their copolymers which have a well-established phase diagram have been studied with temperature-modulated differential scanning calorimetry (TMDSC). All the analyzed polymers have more than one disordering transition between the glass transition (from 400 to 430Â K) and decomposition (starting at â700Â K). Above the glass transition, the reversible heat capacity, Cp, increases beyond that calculated from the crystallinity and the known Cp of the solid and melt. This is likely due to an increase of mobility within the crystals and/or a possible rigid-amorphous fraction (mainly for the copolymers). The disordering transitions are largely irreversible, supporting the observation that semicrystalline, linear macromolecules show decreasing amounts of locally reversible melting with increasing rigidity and crystal perfection.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 471, Issues 1â2, 30 May 2008, Pages 90-96
Journal: Thermochimica Acta - Volume 471, Issues 1â2, 30 May 2008, Pages 90-96
نویسندگان
J. Ma, A. Habenschuss, B. Wunderlich,