Gelatin is a water-soluble natural polyampholyte with poor mucoadhesive properties. It has traditionally been used as a major ingredient in many pharmaceuticals, including soft and hard capsules, suppositories, tissue engineering, and regenerative medicine. The mucoadhesive properties of gelatin can be improved by modifying it through conjugation with specific adhesive unsaturated groups. In this study, gelatin was modified by reacting with crotonic, itaconic, and methacrylic anhydrides in varying molar ratios to yield crotonoylated-, itaconoylated-, and methacryloylated gelatins (abbreviated as Gel-CA, Gel-IA, and Gel-MA, respectively). The successful synthesis was confirmed using ¹H NMR, FTIR spectroscopies, and colorimetric TNBSA assay. The effect of chemical modification on the isoelectric point was studied through viscosity and electrophoretic mobility measurements. The evolution of the storage (G') and loss (G'') moduli was employed to determine thermoreversible gelation points of modified and unmodified gelatins. The safety of modified gelatin derivatives was assessed with an in vivo slug mucosal irritation test (SMIT) and an in vitro MTT assay utilizing human pulmonary fibroblasts cell line. Two different model dosage forms, such as physical gels and spray-dried microparticles, were prepared and their mucoadhesive properties were evaluated using a flow-through technique with fluorescent detection and a tensile test with ex vivo porcine vaginal tissues and sheep nasal mucosa. Gelatins modified with unsaturated groups exhibited superior mucoadhesive properties compared to native gelatin. The enhanced ability of gelatin modified with these unsaturated functional groups is due to the formation of covalent bonds with cysteine-rich subdomains present in the mucin via thiol-ene click Michael-type addition reactions occurring under physiologically relevant conditions.

Mixtures containing polyvinyl alcohol (PVA) and methylcellulose (MC) were obtained and used to synthesize hydrogels in various ratios of components. The swelling kinetics of the resulting hydrogels were studied, revealing that the equilibrium swelling degree in artificial saliva is nearly twice as high as in water. It was found that increasing the volumetric content of PVA in the mixture leads to a higher swelling degree. The kinetics of active pharmaceutical ingredient (API) sorption and release from the hydrogels were also investigated. It was demonstrated that hydrogels with a higher PVA content exhibit greater sorption capacity; however, the release of the API from such samples occurs at a slower rate. For the first time, the mucoadhesive properties of PVA-MC-based hydrogels were studied. It was established that the PVA-MC hydrogel with a ratio of 6:4 vol.% remained on the surface of the porcine cheek mucosa for two days, the 5.5:4.5 vol.% sample detached after 24 h, and the 5:5 vol.% sample adhered for approximately 10 h. These findings confirm the mucoadhesive potential of the hydrogels and their suitability for buccal drug delivery forms. The synthesized PVA-MC hydrogels are promising for applications in medicine and pharmacology.

In this study, polymer films based on polyvinyl alcohol (PVA), modified starch, and acrylic acid (AA) were synthesized and characterized. For the first time, this work investigates the synergistic effect of incorporating AA into films based on PVA and preirradiated starch. Unlike conventional approaches that rely on simple blending of PVA and starch, the use of AA as a functional monomer enables the formation of a chemically cross‐linked structure, where the carboxyl groups of AA establish additional hydrogen and covalent bonds with the hydroxyl groups of PVA and starch, as confirmed by FTIR spectroscopy. Furthermore, this study employs starch that has been pretreated with electron beam irradiation, which enhances component compatibility and improves the mechanical and thermal properties of the films. A comprehensive analysis of the main physicochemical properties of the films showed that increasing the AA content led to a rise in gel fraction yield from 67.4% to 86.2%, indicating a denser cross‐linked polymer network. Thermogravimetric analysis demonstrated improved thermal stability with increasing AA content, with the decomposition temperature reaching up to 450°C and total mass loss reduced to 50%. Mechanical testing revealed a significant enhancement in strength and elasticity: The tensile strength increased from 300 to 500 kPa, and the Young’s modulus increased from 0.3897 to 0.5514 kPa. The obtained results suggest that PVA/starch/AA films hold great potential as a promising material for biodegradable packaging applications.

Thermal insulating materials based on diatomite with burnable and reinforcing additives modified with synthetic and natural polymers have been developed. A mixture of polyvinyl alcohol and starch was used as modifying polymers. The parameters of linear shrinkage, density, tensile strengths in compression and bending, as well as the coefficient of thermal conductivity of the material were determined depending on the concentration and ratio of polymers. It was established that polymer additives had a positive effect on almost all specified characteristics of thermal insulating materials. For example, when adding polymers up to 1 mass.%, the linear shrinkage coefficients decrease from 14.5 to 4.5%, the ultimate compression strengths increase from 0.22 to 2.51 MPa, the ultimate bending strengths increase from 0.2 to 1.26 MPa, the coefficients of thermal conductivity decrease from 0.068 to 0.049 W/m∙K. The densities of materials are in the range of 0.592-0.491 g/cm3. The results of the work showed that the obtained heat-insulating materials can be used as plasticizers in the field of thermal energy.

The flotation of finely divided chalcopyrite and quartz was investigated using a combined reagent system based on butyl xanthate and a thermosensitive cationic copolymer. Copolymers of [2-(methacryloyloxy)ethyl]trimethylammonium chloride and N-vinylcaprolactam (co(METAC/NVCL)), prepared by RAFT polymerisation, were used as the polymer components. Their structure and physicochemical properties were investigated using IR and NMR spectroscopy, gel permeation chromatography and thermal analysis. Flotation tests were carried out on an artificial mixture of chalcopyrite and quartz in a mass ratio of 1:1 at pH 8.5 and temperatures of 20–50 °C. At 40 °C, the combined use of a 70:30 copolymer and butyl xanthate, with each component at a concentration of 5 mg/L, resulted in a copper recovery of 77.68% when the copper content in the concentrate was 30.90%, and a SiO₂ recovery of 5.78%. Compared with the xanthogenate process, copper recovery increased by 5.62%, whilst SiO₂ recovery decreased by 1.10%.