کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7783827 | 1500574 | 2018 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Synthesis and characterization of carboxymethylcellulose grafted with thermoresponsive side chains of high LCST: The high temperature and high salinity self-assembly dependence
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Graft copolymers based on carboxymethylcellulose (CMC) and thermosensitive polyetheramines (ethylene oxide/propylene oxideâ¯=â¯33/10 and 1/9) were prepared in water, at room temperature, by using a carbodiimide and N-hydroxysuccinimide as activators. SLS was applied to obtain Mw, A2 and Rg of CMC and its derivatives. Amide linkages were evidenced by FTIR and grafting percentage was determined by 1H NMR. TGA demonstrated that copolymers were thermally more stable than their precursors. DLS, UV-vis and rheological measurements revealed that properties were salt- and thermo-responsive and linked to the polysaccharide/polyetheramine ratio and the hydrophobicity of the graft. None of the copolymers showed cloud point temperature (Tcp) in water, but they turned turbid in saline media when heated. Copolymers exhibited thermothickening behaviour at 60â¯Â°C (>Tcp) in saline media. Below their Tcp, they showed the ability of keeping constant viscosity or even slight increase it, which was interpreted in terms of intermolecular hydrophobic associations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 184, 15 March 2018, Pages 108-117
Journal: Carbohydrate Polymers - Volume 184, 15 March 2018, Pages 108-117
نویسندگان
NÃvia do N. Marques, Rosangela de C. Balaban, Sami Halila, Redouane Borsali,