Study of the effect of temperature and duration of hydrothermal exposure on the stability of acrylate terpolymers

Abstract

Dynamic light scattering, capillary viscometry, and IR-Fourier spectroscopy have been used to study the effect of temperature and duration of hydrothermal exposure on the chemical composition and structure of acrylate ionic terpolymers of acrylamide (AA), acrylonitrile (AN), and sodium salt 2- acrylamide-2-methylpropanesulfonic acid (AMPSNa) AA-AN- AMPSNa. It has been established that an increase in the duration and temperature of exposure increases the effect of thermo- hydrolysis on the colloidal characteristics of the terpolymer, namely, the average hydrodynamic size of the solvated macromo- lecular polymer coils decreases. A relationship has been established between the chemical composition and structure of the initial terpolymer and the chemical composition and structure of polymer fragments formed after hydrothermal exposure. It has been determined that the increase in stability during thermohydrolysis is associated with the presence of nitrile and sulfo- nate substituents in the side groups of the polymer chain. It has been shown that the AA and AN units of the acrylate terpoly- mer are primarily subjected to thermal treatment. A noticeable change in the composition of the terpolymer after thermohy- drolysis is observed for 5 hours at an exposure temperature of 180 °C, and for 3 hours at 200 °C.