THE STUDY OF RHEOLOGICAL BEHAVIOR AND SAFETY METRICS OF NATURAL BIOPOLYMERS

Traditionally, plastics are made from artificial synthetic polymers. These polymers have an unnatural structure, that's why they are not biodegradable. Based on the latest advances in polymers structure studies, the article sets forward new biodegradable materials highly competitive with base plastic. Biodegradable films were received by fill-and-drain method from agar-agar, carrageenan and hydroxypropyl methylcellulose with glycerol, used as a plasticizer. Various compositions of biodegradable films based on natural polysaccharides have been analyzed for their rheological behavior and stress-strain properties, as well as for their safety and ecotoxicity index. It is found that all compositions of received polymer films are biodegradable and relatively bio-safe (III-IV class of danger). The strength characteristics tests revealed that the compositions with carrageenan have higher strength (2.84 MPa) than polymers containing only agar-agar (1.64 MPa). Also biopolymers with the content of carrageenan have the elevated chemical resistance (prolonged time of dissolution in hydrochloric acid). The melting point of the samples narrowly varies from 35.3 to 35.9°C. The study of the received polymers showed no cracks and no serious heterogeneities of composition. According to the testing results the compounds have been selected, which have optimum characteristics for use of biodegradable polymers in various industries. The biopolymers obtained in the future will replace artificial polymers that can solve problems of non-biodegradable polymer systems waste.