WATER SOLUBLE COPOLYMERS OF ALIPHATIC AND CYCLIC N-VINYLAMIDES WITH N-VINYLIMIDAZOLE AS EFFECTIVE EXTRAGENTS OF HISTIDINE

Abstract

The aim of this work is synthesis of copolymers of N-vinylcaprolactam (VC), N-vinylformamide (VF) with N-vinylimidazole VI for investigation their histidine extraction properties. The copolymers of N-vinylcaprolactam, N-vinylformamide with N-vinylimidazole are synthesized by free radical copolymerization in propanol-2 and dioxane solutions with initiator azobis(isobutyronitrile). Copolymer compositions are determined by UV-spectroscopy and FTIR and copolymerization constants r1 and r 2 for N-vinylformamide and N-vinylimidazole comonomers are calculated. The calculated values of r1 and r 2 equaled rVF = 0.76±0.04 F rVI = 0.77±0.04 demonstrate same relative I activity of comonomers. Complex ability between copolymer macromolecules and histidine is proved by UV-spectroscopy and FTIR. Two-phases water-salt systems containing ammonium sulfate as salting-out agent based on synthesized copolymers are proposed for histidine liquid extraction. Extraction ef ciency of two phase systems containing synthesized copolymers decreases in next order VC-VI > VF-VI > VC-VF. Higher extraction ef ciency of VI containing copolymers is due to basic property of «pyridine» N atom of imidazole cycle. It found that extraction ef ciency of synthesized copolymers correlates with hydrodynamic radii Rh of macromolecules of synthesized copolymers in aqua solution: with increasing of Rh values increases degree of extraction. 2). To sum up copolymers of N-vinylcaprolactam, N-vinylformamide with N-vinylimidazole are synthesized by free radical copolymerization and their extraction properties for histidine are investigated.

Keywords

• copolymers
• N-vinylcaprolactam
• N-vinylformamide
• N-vinylimidazole
• extraction
• histidine.