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The compositions of polymer biodegradable films based on polyhydroxybutyrate and chitosan, cross-linked with calcium chloride, have been developed. New materials, which are promising for use in the field of medicine as wound coverings, suture materials and tissue engineering, have been obtained by casting method. The effect of prescription parameters such as the content of plasticizer and calcium chloride on the physic-chemical properties of polymer compositions has been studied. It is shown that by varying the component content, it is possible to regulate the physic-mechanical properties of the material. It has been established that the addition of calcium chloride, used as a cross-linking agent, determines the porosity of a biopolymer film. The optimal ratios of reagents in polymer composition were selected for their use as implant materials. [ABSTRACT FROM AUTHOR]

In this paper, a mixture PVC/PHB was filled with a natural filler, such as wood flour (WF), was investigated. These polymeric composites were obtained by rolling. Thermal, thermomechanical and mechanical properties of polymer composites based on PVC containing various amounts of wood flour are studied. It has been determined by differential scanning calorimetry method that the glass transition temperature of PVC decreases with a decrease in the percentage of PVC in the mixture. For these composite materials, the TMA method yields flow curves, thermomechanical curves. Thermomechanical analysis shows that different types of wood flour have a different effect on the value of the softening temperature and yield strength of polymer composites.Thermogravimetric analysis shows that despite the decrease in the proportion of PVC in the mixture, the thermal stability of polymer composites filled with rice husk and beech without lignin remains the same. [ABSTRACT FROM AUTHOR]

In this paper, a PVC filled with a biodegradable polymer, such as polyhydroxybutyrate, was investigated. Polyhydroxybutyrate is a natural biopolymer, but its use limits its high cost. These polymeric composites were obtained by rolling. Thermal and thermomechanical properties of polymer composites based on PVC containing various amounts of polyhydroxybutyrate are studied. It has been determined by differential scanning calorimetry method that the glass transition temperature of PVC decreases with increasing percentage of polyhydroxybutyrate filling. For these composite materials, the TMA method yields flow curves, thermomechanical curves. It is determined that unfilled PVC shows a slight deformation and the smallest irreversible deformation. With an increase in the PHB content, both elastic deformation and a viscous flow increase in polymer composites, i.e. with increasing the proportion of polyhydroxybutyrate in the mixture, the elastic properties of the composite increase. Thus, in general, the addition of polyhydroxybutyrate does not significantly impair the performance properties of the resulting composite materials. [ABSTRACT FROM AUTHOR]

In the current work, a series of poly(sodium acrylate)-co-acrylamide (polyNaA-co- AAm/pectin and polyNaA-co-AAm/bentonite) superabsorbent composites were prepared using pectin, bentonite, acrylamide and acrylic acid (AA) in the presence of N,N-methylenebisacrylamide (MBAAm) as cross-linker and a mixture of ammonium persulfate and TEMED as initiator. The structure and sorption capacity of the developed composites were characterized by Fourier transform infrared spectroscopy (FTIR), voltammetry and UV-visible spectroscopy. In this paper, the sorption capacity of a series of samples of composite materials polyNaA-co-AAm/pectin and polyNaA-co- AAm/bentonite were determined and compared. Studies and the analysis of absorption processes of copper ions from aqueous solutions showed that the pectin and bentonite-containing polymer composites has high degree of affinity with of heavy metal ions. Developed pectin-containing hydrogel composite can be effectively used for removal from water solutions of toxic connections. [ABSTRACT FROM AUTHOR]

In order to reduce the negative impact of PVC on the environment, it is becoming popular to produce composite materials based on PVC filled with various natural fillers. For example, bentonite as filler in a polymer matrix can absorb volatile toxic components and accelerate the degradation of PVC. Also in this paper, natural polysaccharides pectin and starch are considered as fillers. Pectin and starch are also capable of accelerating biodegradation of PVC. Nevertheless, the thermal stability of the resulting polymer composites is also of interest. For these polymeric composites, the thermal stability was studied by thermogravimetry, the destruction mechanism was studied, and the kinetic parameters of the thermal destruction were determined. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO) are a promising material for a variety of applications due to their unique characteristics and properties, including optical, chemical, semiconductor and piezoelectric. A lot of scientific papers are devoted to the antibacterial action of ZnO nanoparticles. As the main mechanism responsible for the antimicrobial action of ZnO in modern studies, photocatalytic generation of hydrogen peroxide H2O2 is indicated. In addition, in a number of studies it was found that the slowing of bacterial growth upon contact with ZnO is due to the penetration of nanoparticles and the subsequent destruction of the cell membrane. The size effect of antibacterial activity of ZnO nanoparticles has not been fully established and opinions differ on this score: it was shown in that smaller ZnO nanoparticles have a higher toxicity, however, Franklin et al showed that the antimicrobial effect of ZnO is not depends on the size of the nanoparticles. As shown by the studies described in previous works, polymeric nanocomposites based on acrylates with ZnO nanoparticles show pronounced antifungal and antibacterial activity. However, some antifungal activity is also manifested by a polymer matrix based on acrylate monomers that does not contain ZnO nanoparticles. This work is devoted to the study of chemical processes of hydration of nanocomposite polymeric materials with and without ZnO nanoparticles introduced. Polymer matrices based on UV-polymerization acrylates of 2-Carboxyethyl acrylate (2Carb, Aldrich No. 552348) and Bisphenol A glycerolate (1 glycerol / phenol) diacrylate (Bis A, Aldrich No. 411167) were investigated. As filler, ZnO (local Russian supplier REACHEM, powder) was used. Polymer matrices of two-component composition were synthesized, one with the inclusion of ZnO nanoparticles, the other without them. The IR spectra of the resulting composites, as well as the IR spectra of the substances released into the water from the polymer matrixes, were analyzed. Study of IR spectra allows us to conclude that when placing the composite with ZnO nanoparticles in the water, more monomers and monomer salts are released into the aqueous medium, and an increased release of the carboxylate anion occurs as compared to the polymer that does not contain ZnO nanoparticles, which exhibit antifungal properties. Thus, this polymer composite is promising for applications in medicine, cosmetology and paint and varnish manufacture. [ABSTRACT FROM AUTHOR]