Experimental modeling of biodegradable microplastics

The accumulation of microplastics (MP) in the environment has become particularly relevant. When polymers decompose under the influence of external factors, particles of various shapes and sizes with a "developed" surface appear. The possible negative impact of MP on living organisms is associated with its ability to adsorb and transport various chemicals, often toxic, and biological objects from the external environment, such as bacteria and microorganisms. Recent findings have highlighted the role of biodegradable polymers in the production of new material. Obviously the contamination of the surface of biodegradable MP particles can significantly slow down the rate of its decomposition. Nowadays there are practically no investigations on the processes of biodegradation of such «decorated» particles. Therefore, it is now important to find model systems of appropriate composition, size and morphology, to study the physicochemical aspects of MP interaction with various "pollutants" and to study the effect of adsorbed substances on the rate of biodegradation. Cellulose particles were used as model of biodegradable MP. Aggregative-stable particles with the average hydrodynamic diameter of 300-800 nm were obtained. The negatively charged cellulose particles were modified with a p̈ollutant-̈ a cationic polymer, caustamine, used for wastewater treatment. The composition of the resulting complexes and their ability to dissociate into the initial components in water-salt media under various conditions (temperature, pH, salt concentration) were studied. The influence of the "pollutant" on the rate of biodegradation of MP under the action of enzymes was investigated. Acknowledgments The work was carried out within the project: "Modern problems of chemistry and physical chemistry of macromolecular compounds" (AAAA-A21-121011990022-4). Also see: https://micro2024.sciencesconf.org/559701/document