Synthesis and properties of grafted copolymers of xanthan and glucomannan with acrylic monomers

Abstract

Graft copolymers of polysaccharides with acrylic monomers combine biodegradability, biocompatibility, the environmental friendliness of natural polymers and the increased thermal stability, chemical and mechanical resistance of synthetic polymers. This paper describes our search and analysis of the literature in English for 2002–2022 devoted to the graft polymerization of acrylamide, acrylic acid and 2-acrylamido- 2-methylpropanesulfonic acid onto xanthan and glucomannan macromolecular chains. It has been found that the synthesis of grafted copolymer chains proceeds by a radical polymerization mechanism using thermal homolytic decomposition of the initiator or microwave irradiation, or radiation initiation and frontal polymerization in some cases. Depending on the method of the reaction, the synthesis time of a graft copolymer varies from several minutes to several hours. The influence of the synthesis conditions and parameters on the monomer conversion, structure and properties of the resulting polymer has been considered. It has been found that decreasing the polysaccharide/monomer ratio and increasing the initiator concentration raise the efficiency and degree of grafting. Several methods for characterization of graft copolymers are discussed, including: IR spectroscopy to analyze the chemical structure of a sample, scanning electron microscopy to characterize structure, supramolecular ordering and porosity, differential thermal analysis to evaluate thermal effects and thermal stability. The effect of the synthesis conditions and the pH of the sorption medium on the water absorption and sorption capacity of this class of graft copolymers are discussed. The broad potential of graft copolymers for repeated cycles of absorption and release of liquid medium without loss of functional properties has been found. This opens prospects for the use of graft copolymers of xanthan and glucomannan with acrylic monomers as materials for water purification from metal ions and cationic dyes, targeted delivery and prolonged action of drugs and wound coatings for wound treatment.