کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5206838 | 1382323 | 2012 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
In-situ monitoring by fibre-optic NIR spectroscopy and rheometry of maleic anhydride grafting to polypropylene in a laboratory scale reactive extruder
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The graft copolymerisation of maleic anhydride (MAH) onto polypropylene (PP) has been studied in situ by interfacing a laboratory scale mini-extruder/processor with a near-infrared (NIR) spectrometer via a fibre optic link. Apparent viscosity was measured simultaneously with the NIR spectra. The graft reaction was carried out at several temperatures with and without the initiator, dicumyl peroxide (DCP). Analysis of the NIR spectra showed the reaction to be first order with respect to MAH, and that the graft reaction rate was not affected by the presence of DCP. However, DCP caused a large increase in chain scission reactions leading to a dramatic drop in apparent viscosity. In the absence of DCP, scission reactions occurred at a slower rate and the apparent viscosity remained steady, after an initial drop, for about 15Â min during the early part of the reaction. We suggest that a possible explanation for this might be a “repair mechanism” involving the reaction of two PP macro-radicals with a single MAH moiety, thus maintaining the molecular weight. Once the concentration of MAH drops, this reaction becomes less significant and scission reactions dominate.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Testing - Volume 31, Issue 1, February 2012, Pages 155-163
Journal: Polymer Testing - Volume 31, Issue 1, February 2012, Pages 155-163
نویسندگان
Lalehvash Moghaddam, Llewellyn Rintoul, Peter J. Halley, Graeme A. George, Peter M. Fredericks,