Preparation and Characterization of Starch Active Interface Calcium Carbonate for Biodegration

Calcium carbonate is so hard to be further developed in polymer applications because it is difficult to combine with other materials. Starch-coated calcium carbonate was prepared by using starch as the main modifier and sodium stearate and sodium hexametaphosphate as the auxiliary modifiers. Optimal modification conditions were tested by single factor experiment and orthogonal experiment optimization. Manifestation was evaluated with the help of Fourier infrared spectrometer (FT-IR) and laser particle size analyzer and other test instruments. Results showed that a starch film was successfully coated on the surface of calcium carbonate, and the edges and corners of the modified coated calcium carbonate were passivated, and the particles were rounded. The active interface calcium carbonate has a broad application prospect in the field of degradable biomaterials.

Properties of Polypropylene Yarns with a Polytetrafluoroethylene Coating Containing Stabilized Magnetite Particles

This paper describes an original method for forming a stable coating on a polypropylene yarn. The use of this method provides this yarn with barrier antimicrobial properties, reducing its electrical resistance, increasing its strength, and achieving extremely high chemical resistance, similar to that of fluoropolymer yarns. The method is applied at the melt-spinning stage of polypropylene yarns. It is based on forming an ultrathin, continuous, and uniform coating on the surface of each of the yarn filaments. The coating is formed from polytetrafluoroethylene doped with magnetite nanoparticles stabilized with sodium stearate. The paper presents the results of a study of the effects of such an ultrathin polytetrafluoroethylene coating containing stabilized magnetite particles on the mechanical and electrophysical characteristics of the polypropylene yarn and its barrier antimicrobial properties. It also evaluates the chemical resistance of the polypropylene yarn with a coating based on polytetrafluoroethylene doped with magnetite nanoparticles.

Impact of lead acetate and sodium and potassium stearates on lipid peroxidation processes in the body of experimental animals

Introduction. Given the significant prevalence of lead in the environment, research in this area has significant social and economic importance. Lead compounds are characterized by high toxicity and increased ability to cumulate in ecosystems, humans, and animals. Lead enters the human body with food, drinking water, atmospheric air, and smoking. Lead causes pathological changes in the nervous system, blood-forming organs, kidneys, etc. Materials and methods. The experiments were carried out on four groups of white female rats, each included seven animals, weighing 150-200 g. The first group of animals was a control. The second group consumed dechlorinated water from the city water supply, followed by lead acetate. The animals from the third and fourth groups drank the same water with sodium stearate and potassium stearate content in a dose of 1/250 LD50. After the 40th-day of the use of these waters, the animals were orally administered lead acetate at a dose of 7 mg/kg. The levels of lipid peroxidation biomarkers were studied by studying the content of diene conjugates (DC) and malondialdehyde (MDA) in blood serum, liver, and kidney homogenates. Results. The administration of 1/2 acetate LD50 to lead in experimental rats drinking water with stearates was accompanied by a significant increase in the DCs concentration and (MDA) in animals. Higher concentrations of LPO products were observed in the group of animals that consumed water from potassium stearate. Conclusions. 1. With the oral administration of lead acetate against the background of drinking water containing stearates at a dose of 1/250 LD50, an increase in lipid peroxidation indices was noted compared with the control group. 2. Higher concentrations of LPO products were observed in the group of animals consuming water from potassium stearate.

Synthesis of New Naphthyl Aceto Hydrazone-Based Metal Complexes: Micellar Interactions, DNA Binding, Antimicrobial, and Cancer Inhibition Studies

In the present study, naphthyl acetohydrazide (HL) ligand was prepared and used for the synthesis of new six amorphous transition metal (Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II)) complexes. All the compounds were characterized by elemental analysis, UV-vis, FT-IR, 1H- and 13C-NMR, and Matrix-Assisted Laser Desorption Ionization (MALDI). The solubilization study was carried out by estimating the interaction between the metal complexes with surfactants viz. sodium stearate (SS) and Cetyltrimethylammonium bromide (CTAB). UV-Visible spectroscopy was employed to determine partitioning and binding parameters, whereas electrical conductivity measurements were employed to estimate critical micellar concentration (CMC), the extent of dissociation, and free energy of micellization. The CT-DNA interaction of synthesized compounds with DNA represents the major groove binding. The synthesized ligand and metal complexes were also tested against bacterial and fungal strains and it has been observed that Cu(II) complex is active against all the strains except Candida albicans, while Cd(II) complex is active against all bacterial and fungal strains except Pseudomonas. Among all compounds, only the Pd(II) complex shows reasonable activity against cervical cancer HeLa cell lines, representing 97% inhibition.

Synergistic effect of aluminum diethylphosphinate/sodium stearate modified vermiculite on flame retardant and smoke suppression properties of amino coatings

Schematic illustration of the flame retardant and smoke suppression mechanism of ANE coatings during the combustion process.

Nonwoven Materials Produced by Melt Electrospinning of Polypropylene Filled with Calcium Carbonate

Nowadays, polypropylene-based nonwovens are used in many areas, from filtration to medicine. One of the methods for obtaining such materials is melt electrospinning. In some cases, it is especially interesting to produce composite fibers with a high degree of filling. In this work, the influence of the filling degree of isotactic polypropylene with calcium carbonate on the structure and properties of nonwoven materials obtained by melt electrospinning was studied. It was shown that electrospinning is possible, even at a filler content of 50%, while the average diameter of the fibers increases with the growth in the content of calcium carbonate. The addition of sodium stearate significantly reduces the diameter of the fibers (from 10–65 to 2–10 microns) due to reducing viscosity and increasing the electrical conductivity of the melt. Wide-angle X-ray diffraction analysis and IR spectroscopy reveal that the initial polymer and composites are characterized by the presence of stable α-form crystals, while nonwovens show a predominance of smectic mesophase. The addition of calcium carbonate leads to an increase in the hydrophobicity of the composite films, the addition of sodium stearate results in a decrease of hydrophobicity, while all nonwovens demonstrate superhydrophobic properties.

Preparation of Antimicrobial Fibres from the EVOH/EPC Blend Containing Silver Nanoparticles

The article presents a new fabrication method for bioactive fibres with a microporous structure of ethylene–vinyl alcohol copolymers (EVOH)/ethylene−propylene copolymer (EPC) blends. The experimental work carried out resulted in obtaining EVOH/EPC polymer blends fibres with the addition of glycerol and sodium stearate. Different concentrations of glycerol (38%, 32%) and sodium stearate (2%, 8%) were used to prepare the fibres. The purpose of using different concentrations of stearate and glycerol was to evaluate the effect of additives on the structure and properties of the fibres. A significant influence of the additives used on the morphological structure of the fibres was found. The resulting fibres were modified with an AgNO3 solution and reduced to silver nanoparticles (AgNPs), to give the fibres bioactive properties. The fibres obtained with the addition of 8% stearate have a more developed surface, which may influence the amount of adsorbed silver particles inside the fibre. However, the durability of depositing silver particles after multiple washes has not been tested. Three types of microorganisms were selected to assess the microbiological activity of the obtained fibres, i.e., Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Escherichia coli. The fibres have antibacterial activity against gram positive and negative bacteria. The largest inhibition zones were obtained for gram-positive bacteria Staphylococcus aureus, ranging from 3 to 10 mm depending on the concentration of AgNPs. The morphology of the blends fibres was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). The occurrence of elemental silver was analysed by energy dispersive spectroscopy (EDS) analysis. The changes of the polymer structure chemistry are studied by Fourier transform infrared spectroscopy (FTIR).

Differential Scanning Calorimetric Analysis for Incompatibility: Sodium Stearate/Magnesium Stearate and Acidic Compounds

Compatibility investigation was performed between stearate lubricants (sodium stearate and magnesium stearate) and acidic pharmaceutical compounds (ibuprofen, indomethacin and valproic acid) and citric acid as acidic pharmaceutical excipient using differential scanning calorimetry (DSC). Alteration in DSC thermogram was found in all mixtures. There was a presence of melting endothermic peak of stearic acid in all mixtures (except that of stearate lubricants and indomethacin) indicating breakage of salt form of stearate lubricants depended on the physicochemical properties of drug compounds and pharmaceutical excipient. Therefore, the avoidance for using stearate lubricants with acidic pharmaceutical compounds and excipient should be concerned in development of pharmaceutical formulations.