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 r2 for N-vinylformamide and N-vinylimidazole comonomers are calculated. The calculated values of r1 and r2 equaled rVF = 0.76±0.04 и rVI = 0.77±0.04 demonstrate same relative activity of comonomers. Complex ability between copolymer macromolecules and histidine is proved by UV-spectroscopy and FTIR (fig. 1). Two-phases water-salt systems containing ammonium sulfate as salting-out agent based on synthesized copolymers are proposed for histidine liquid extraction. Extraction efficiency of two phase systems containing synthesized copolymers decreases in next order VC-VI>VF-VI>VC-VF. Higher extraction efficiency of VI containing copolymers is due to basic property of «pyridine» N atom of imidazole cycle. It found that extraction efficiency 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 (fig. 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.

ACKNOWLEDGEMENTS

The FTIR data were obtained with equipment  of Voronezh State University Center  for Collective Use of Scientific Equipment.