کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5188141 | 1381147 | 2007 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The role of methyl methacrylate on branching and gel formation in the emulsion copolymerization of BA/MMA
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The effect of the monomer ratio on the microstructure of BA/MMA emulsion copolymers was investigated. Monomer ratios spanned from pure BA used for adhesives to 50/50 wt/wt BA/MMA copolymers used for coatings. The gel content varied from 55% for pure BA to nil for the 50/50 copolymer. The branching level was reduced from 2.6% for pure BA to 0.3% for a 75/25 BA/MMA copolymer. The mechanisms responsible for the reduction of gel content can be found in the lower reactivity of the MMA terminated chains for hydrogen abstraction, the absence of abstractable hydrogens in the MMA units and the fact that MMA radicals terminate predominantly by disproportionation. The reduction of the level of branches is mainly due to the lower reactivity of MMA for intramolecular transfer and the lower instantaneous conversions that favored propagation over backbiting.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 48, Issue 9, 24 April 2007, Pages 2542-2547
Journal: Polymer - Volume 48, Issue 9, 24 April 2007, Pages 2542-2547
نویسندگان
Iñigo González, José M. Asua, José R. Leiza,