کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
693008 889862 2012 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Grafting sites of acrylic mixed monomers onto unsaturated fatty acids: Part 2
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تکنولوژی و شیمی فرآیندی
پیش نمایش صفحه اول مقاله
Grafting sites of acrylic mixed monomers onto unsaturated fatty acids: Part 2
چکیده انگلیسی

Acrylic groups were grafted onto alkyds via free radical chemistry. The alkyd comprised soybean oil, glycerol, phthalic anhydride, and tetrahydrophthalic anhydride. To closely model acrylated-alkyds, a mixture of four acrylic monomers were copolymerized with the alkyd including: methyl methacrylate (MMA), butyl acrylate (BA), methacrylic acid (MAA), and vinyltrimethyoxysilane (VTMS). Two different initiator systems were used, benzoyl peroxide (BPO) and 2,2′-azobisisobutyronitrile (AIBN), for comparison. To elucidate the grafting sites, 1D NMR spectroscopy and 2D NMR spectroscopy were used. Gradient heteronuclear multiple quantum correlation (gHMQC) was needed to assign the chemical shifts of the 1D carbon and proton NMR spectra. The gHMQC spectra provided evidence of acrylic–alkyd grafted structures formed at doubly allylic hydrogens located on the fatty acid chains. As a side reaction, acrylic groups were grafted into the polyester backbone of the alkyd via hydrogen abstraction of the glycerol. The gHMQC spectra show no evidence of grafting across double bonds on either the fatty acid side chains or the THPA backbone. It was also determined that choice of initiator has no effect on graft location. However, the system initiated with BPO provided spectral evidence of the formation of benzoic acid, which shows that the peroxide initiator can directly abstract the doubly allylic hydrogen. The side product, isobutyronitrile did not appear in the spectra obtained from the AIBN initiated system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Organic Coatings - Volume 73, Issue 4, April 2012, Pages 308–320
نویسندگان
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