Properties of cross-linked copolymers of polypropylene glycol maleate with acrylic acid obtained at various concentrations of the RAFT agent

The initial polypropylene glycol maleate has been obtained by the polycondensation reaction of maleic anhydride and propylene glycol. The molecular weight of the synthesized unsaturated polyester resin has been determined. The copolymers under study have been obtained by radical copolymerization of p-PGM. The possibility of synthesizing new polymers based on p-PGM with acrylic acid in the presence of a RAFT agent has been shown. The effect of RAFT agent concentration on the network density and product yield has been studied. It has been found that the yield of the cross-linked polymer decreases, its swelling capacity increases, and the yield of the linear polymer increases with an increase in the RAFT agent concentration. The effect of organic solvents, pH, and low-molecular-weight salts on the swelling degree of the synthesized copolymers has been investigated. The research results demonstrate that the susceptibility of polymer hydrogels to organic solvents and changes in pH, and low molecular weight salts, is affected by the amount of RAFT agent in the polymer. The synthesized objects have been characterized by infrared spectroscopy. Scanning electron microscopy has estimated the polymer surface morphology and pore sizes.