STUDYING THE NUANCES OF THE POLYACRYLAMIDE HYDROGELS SYNTHESIS BY THE FRONTAL POLYMERIZATION METHOD UNDER TECHNOLOGICAL CONDITIONS

Abstract

Polyacrylamide hydrogels (PAHs) with controllable properties are synthesized in a pilot plant using the frontal polymerization (FP) method by controlling the flow rate and temperature of the starting mixture, the power of the UV lamp, and eliminating the adhesion between the reactor walls and the PAH. Due to the specifics of the FP method, in order to regulate the absorption and release of water and active substances, according to the required physical-mechanical properties, PAH studies are carried out under certain conditions at various ratios of monomers with additives of natural origin, including nano- sized ones. The specificity of FP, in contrast to traditional polymerization methods, lies in the implementation of the polymerization process not in the entire volume of the reacting mass, but along the reaction unit according to the mechanism of autowave propagation of the process. A study on the influence of various kinetic and macrokinetic parameters on the stationarity of the FP process is conducted. The amount of water and active substances absorbed and released from the synthesized PAHs in frontal reactors, as well as the absorption time, are controlled. The linearity of the PAH synthesis process was ensured, a stable process mode was maintained throughout the current process cycle. The non- stationarity of the front wave leads to the extinction of the propagating wave, the combustion of the catalyst, the mass exchange, the violation of adiabaticity due to the influence of the external environment and the occurrence of various non-linear phenomena, therefore the inhomogeneity of the obtained product. The ecological safety and purity of the obtained product from the toxic monomer, acrylamide were provided. Even traces of

acrylamide are completely absent in PAHs synthesized by the FP method, which is due to the specificity of the FP process itself. The kinetics of water absorption and release of the obtained hydrogels and the possibilities of their application for agricultural purposes are studied: their effectiveness in the process of rapid germination and growth of wheat seeds is proved.