کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10603314 | 982474 | 2013 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular weight distribution and functional group profiles of TEMPO-oxidized lyocell fibers
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The effects of TEMPO-mediated oxidation, performed with NaClO, a catalytic amount of NaBr, and 2,2â²,6,6â²-tetramethylpiperidine-1-oxy radical (TEMPO), were studied on lyocell fibers by means of GPC using multiple detection and group-selective fluorescence labeling according to the CCOA and FDAM methodology. The applied method determines functional group content as a sum parameter, as well as functional group profiles in relation to the molecular weight of the cellulose fibers. Both the CHO and COOH profiles, as well as molecular weight alterations, were analyzed. A significant decrease in the average molecular weight was obtained during the first hour of TEMPO-mediated oxidation, but prolonged oxidation time resulted in no strong additional chain scission. Significant amounts of COOH groups were introduced in the high molecular weight fractions by the oxidation with higher concentrations of NaClO (2.42-9.67Â mmol NaClO/g fiber) after modification times of 1Â h or longer.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 98, Issue 1, 15 October 2013, Pages 444-450
Journal: Carbohydrate Polymers - Volume 98, Issue 1, 15 October 2013, Pages 444-450
نویسندگان
Jovana Milanovic, Sonja Schiehser, Predrag Milanovic, Antje Potthast, Mirjana Kostic,