Preparation of Mixed Hydrogels Based on Biopolymers and the Study of Their Rheological Properties

Abstract

A well-known, affordable, and cheap method of modifying biopolymers is their simple mixing with synthetic and natural polymers. As a result, similar to metal alloys, polymer-polymer complexes with predetermined properties can be obtained. Although interpolymer complexes became a subject of study and application a long time ago, in domestic practice, the study of natural biopolymers is limited. The purpose of this study was to present and study the issue of structuring in solutions of bio- and synthetic polymers, as with a low dry matter content such structures have many properties of a solid. Natural ampholytic polymers are polyelectrolytes, which is also of great importance for their further study. By analyzing the results of studies of complexes formed by a synthetic linear polyelectrolyte with a charged partner – protein, it becomes possible to create new “smart” polyelectrolyte complexes that can undergo phase changes in narrow, controlled pH ranges. The positive effect of sodium carboxymethyl cellulose on the gelation of 5% gelatine hydrogels was established. It was determined that the presence of additives of inorganic salts leads to an increase in the swelling of gelatine gels. It was established that more durable gels are less prone to aging. The practical significance of these studies is determined by the fact that in many industries (food, soap, paint, and varnish), it is necessary to obtain structures with tailor-made properties. Gel formation may also be an undesirable phenomenon that must be prevented, for example, in the production of chemical fibers, glues, and tanning solutions. Furthermore, biological objects themselves in most cases, by their nature, are protein gels with specific mechanical properties. Keywords: structure and dynamics of gelatine mixed hydrogels, adsorption on solid surfaces, collapse of heterogeneous networks, swelling and aging of mixed gelatine hydrogels.

Oxidation reactions of cyclopent-2-en-1-yl thiophene derivatives

“…In practice, the possibility of obtaining thiophene oxabicyclohexane derivatives varied depending on the structure of the starting materials. Thus, for 2-(cyclopent-1-en-3-yl)thiophenes, the oxidation of the double bond was easier, while for 2-(cyclopent-1-en-1-yl)-5-methyl-thiophenes it was difficult or occurred synchronously with the oxidation of sulfur in the aromatic core (30)(31)(32)(33) . Modern laboratories use molecular docking for preliminary monitoring of the biological activity of compounds examined.…”