ИСТИНА

Polymer microgels responsive to the influence of temperature and acidity of the medium can be used to obtain different functional materials such as superabsorbents, carriers of drugs and dyes. Using microgels in front of macrogels is more preferable because of shorter response times to external stimuli. The aim of our study is to investigate the properties of microgels based on poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAA) interpenetrating networks (IPN) and to check the possibility to use such microgels for the development of polymer films and coatings. To obtain the microgels with IPN structure, in the first stage, the PNIPAM microgels were synthesized by thermo-induced precipitation polymerization, then the second subnetwork was synthesized by in situ copolymerization of acrylic acid and N,N’-methylenebisacrylamide in the volume of the initial PNIPAM microgels. The influence of different polymerization conditions was studied. The thermo- and pH-responsive behavior of obtained IPN microgels was investigated by dynamic and static light scattering. The formation of second subnetwork didn’t affect the transision temperature (34°C). The pH-induced transition was observed around pH 4.5. It was shown that at the room temperature the IPN particles have a core-shell structure. The sizes and shapes of IPN particles were observed by scanning and transmission electronic microscopy. In the next steps, polymer films will be produced by assembling of IPN miscrogels on different substrates during solvent evaporation and further temperature treatment or crosslinking by multivalent ions. Such films can be used as containers for immobilization of organic dyes and drugs. The work was supported by Russian Science Foundation, grant No. 17-73-20167.