STUDY OF THE FEATURES OF GEL FORMATION AND RHEOLOGICAL PROP-ERTIES OF HYDROGELS BASED ON AGAR-AGAR

The article shows studies on the study of the kinetics of gelation and the features of the rheological properties of hydrogels based on agar-agar. It has been found that hydrogels have attracted a lot of attention in the last 50 years due to their exceptional wide range of applications. They have a certain degree of elasticity, very similar to natural fabrics due to the high water content. Within the framework of the literature review, it has been shown that polymer hydrogels are usually obtained by polymerization of water-soluble unsaturated compounds in the presence of a bifunctional cross-linking agent or by structuring pre-prepared reactive prepolymers. The ability of polymer hydrogels to undergo bulk transitions between swollen and collapsed phases under the action of an external medium is one of the most important and universal properties of these materials. It has been shown that polymer hydrogels are known that are used as inert matrices for the controlled release of pre-absorbed biologically active substances. In this case, the release rate of the biologically active substance is determined by the nature and structure of the hydrogel polymer framework. The article studies the kinetics of gelation and the features of the rheological properties of hydrogels based on agar-agar in order to obtain modern biocompatible materials for the medical, cosmetological and pharmaceutical industries. It is shown that in compositions that consist exclusively of agar-agar and water, the shortest time for loss of stickiness and film formation is observed. At the same time, with an increase in the content of agar-agar from 25 to 50 %, one can see the most rapid processes of loss of stickiness and film formation. Compositions with the longest time for loss of stickiness and film formation were determined, which contain 25 % agar-agar and 50 % milk and honey, because they will be characterized by a long diffusion time of active substances to the human body. The scientific novelty of the study is related to the study of the effectiveness of gelation in conditions of highly concentrated agar-agar solutions with different contents of the polymer part and active substances, on the basis of which compositions for the preparation of face masks and medical tapes are proposed.