Gamma radiation synthesis of stimuli-responsive membranes and hydrogel sorbents based polymers of vinyl ethers and their interpolymer complexes for application in separation processes

Stimuli-responsive hydrogel and film materials have been obtained for application in separation process. Novel polycationic and polyampholyte hydrogels were synthesized by gamma-radiation copolymerization of vinyl ethers of monoethanolamine (VEMEA) and ethyleneglycol as well as VEMEA and acrylic acid. The complex formation of the obtained hydrogels with various metal ions and linear polyelecrtrolytes has been studied. Water soluble and crosslinking thermo-sensitive cationic copolymers based on 2-[(methacryloyloxy)ethyl]trimethylammonium chloride and Nisopropylacrylamide (MADQUAT-NIPAAM) were obtained and their interaction with poly(acrylic acid) (PAA) and potassium hexacyanoferrates (II, III) were studied. It was found that the composition of copolymer significantly affects the composition of polyelectrolyte complexes and molecular weight of PAA influences their aggregation stability. The study of interaction MADQUAT-NIPAAM copolymers with proteins has been started. Novel non-ionic thermo-sensitive linear and crosslinked polymers have been obtained by gamma-irradiation copolymerisation hydrophilic The sorption processes of surfactants by novel thermosensitive copolymers have been studied. Stimuli-resposive films were prepared by gamma-radiation cross-linking of the blends based of poly(acrylic acid) and poly(vinyl methyl ether). The environmental pH affects the swelling of the films significantly. In acidic media the films have lower swelling ability because of suppression of carboxylic groups ionisation and formation of additional physical cross-links via interpolymer hydrogen bonding. Novel polymeric film materials were prepared by radiation grafting of cationic monomer vinyl ether of monoethanolamine on the surface of polyethylene and polypropylene films. The prepared graft copolymers showed a good affinity towards the chelation and/or complexation with different metals investigated here (Pb2+, Cd2+, Zn2+, Fe3+, Cu2+, Ni2+, Co2+, Ag+). Treating of the saturated films with 0.01 HCl at room temperature for one hour easily recover the absorbed metals and accordingly the films can be reused for the resorption of metal ions. The copolymeric hydrogels based on polyethylene glycol (PEG) and methacrylic acid (MAA) have been synthesized by using γ-irradiation copolymerization. Physical chemical characteristics of obtained networks were studied. The comparative study of uranyl ions adsorption by PEG-MAA and polymethacrylic acid (PMAA) hydrogels was carried out. It was shown that the sorption characteristics depend on pH and ionic strength of solution as well as uranyl ions concentration. The higher stability in the regeneration processes and possibility of repeated use of copolymeric hydrogel of PEG-MAA for uranyl ions adsorption in comparison to homopolymer PMAA were shown. (author)