| Autor: |
Toktabayeva, Assel, Rakhmetullayeva, Raikhan, Abutalip, Munziya, Mamutova, Alua, Batyrbayeva, Aigul, Mun, Grigoriy |
| Předmět: |
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| Zdroj: |
Journal of Chemical Technology & Metallurgy; 2019, Vol. 54 Issue 3, p475-482, 8p |
| Abstrakt: |
The polyelectrolyte exhibits the ability of undergoing a phase transition in aqueous solutions with temperature increase only if its macrochain hydrophilic-hydrophobic balance is achieved by a particular combination of hydrophilic nonionic (HEA), hydrophobic (NIPAAm) and ionic (AK) monomers. New polymeric hydrogels are obtained by radical copolymerization of GEA, AK and NIPAAm. Their thermal sensitivity is determined as a function of medium pH and temperature. The hydrogels aqueous solutions are characterized by LCST values which can be controlled by varying the chemical composition of the terpolymer and the environment pH. The copolymerization of N-isopropylacrylamide on maize starch (MS) is carried out at 70°C using ammonium persulfate (APS) as an initiator. The N-isopropylacrylamide-modified copolymers are characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-Ray diffraction (XRD) and thermogravimetric analysis (TGA) techniques. The influence of these copolymers on the physico-mechanical properties of Portland cement (PC) pastes is determined using various characterization methods such as compressive strength, water absorption and workability. It is shown that the terpolymers obtained by HEA-NIPAAm-AK-crosslinking can be effectively used as sorbents in wastewater treatment systems, as well as for concentration and extraction of metal ions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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