کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5203268 1381925 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chemical structures assigned for the low molecular weight fractions from degradation of poly(styrene sulfides)
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Chemical structures assigned for the low molecular weight fractions from degradation of poly(styrene sulfides)
چکیده انگلیسی
A non-destructive analysis is performed of thermally unstable sulfur-styrene reaction products, combining preparative size exclusion chromatography (P-SEC), ultraviolet-visible (UV-vis) and nuclear magnetic resonance (NMR). The crystallizing compounds are identified as be 2,4-diphenylthiophanes with short sulfur bridge (x ∼ 2) contrary to earlier suggestions which were based on destructive analysis. A new cyclic structure (styrene polysulfide x = 1 up to 8) was assigned to the amorphous species containing a single styrene repeating unit. Comparison with the amorphous fractions suggests that the rigid ring of styrene repeating units in adjacent sequences is the characteristic feature for the crystallisability. The melting and crystallization behaviour of this crystalline component was observed, by optical microscopy (OM) and differential scanning calorimetry (DSC), to be step-wise as well as broad, due to the variation in the length of the sulfur bridge.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 95, Issue 2, February 2010, Pages 126-131
نویسندگان
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