The effect of the composition of the polymer composite (type of polyhexamethyleneguanidine (PHMG) salt, content of components) on the structure of the composite formed and level of desorption of the biologically active substance (BAS) was established as a result of studying the kinetics of desorption of BAS from viscose fibres containing PHMG salt and polyalkylene oxide. The possibility of obtaining viscose fibres containing a biologically active substance of the polymer type with a continuous process scheme was demonstrated.Developments aimed at giving fibre materials biological properties have now been extremely intensified, and this concerns not only medical materials but also so-called hygienic textiles. However, the prolonged use of such items for daily wear can have negative consequences, since the low selectivity of the antimicrobials kills all microflora on the skin, which, despite expectations, not only does not reduce the probability of disease, but also negatively affects the immune reactivity of the human body. At the same time, the necessity of developing process methods for manufacturing new types of biologically active fibre materials is obvious due to the demand for them in different sectors (medical articles, filters, etc.).Fibre materials with biological activity resistant to laundering are usually manufactured by chemical addition of the active component to the fibre matrix, conducting the process in one or two stages. In the first case, simultaneous treatment with the biologically active substance (BAS) and modifying reagent is conducted, while in the second case, the matrix is modified first, and then the BAS is added [1]. The drawbacks of both methods include incorporation of the modifier in the matrix, which increases the toxicity of the material in some cases, and can also change the physicomechanical properties of the fibre material, which can be reflected in its consumer properties (feel, color).Methods based on including BAS in the structure of the fibre during spinning or subsequent finishing have been examined in recent years as a promising method of obtaining large-tonnage chemical fibres with biologically active properties [2]. To incorporate the biologically active substance in the spinning solution, it must satisfy a number of requirements related to the spinning conditions, and this limits the list of BAS that can be used [2]. For this reason, the second method is preferred.Of the antimicrobials that can be used to give fibres special properties, biologically active polymers are of great interest. Use of a biopolymer chitosan to give fibre materials biological stability by impregnation and precipitation [3,4] or by adding to a bifunctional compound [4] is well known. However, the poor solubility of chitosan, high viscosity of the solutions, increased rigidity of the materials, and the narrow spectrum of the bacteriostatic action do not allow considering it an effective BAS. Restricted use (not in sufficient doses) for radiation sterilization the most suitable method for this type...
The possibility of synthesizing silatrane-containing polymers was investigated using three different synthetic methods: the formation of silatrane fragments from polymers with trialkoxysilyl groups, the copolymerization of silatrane-containing monomers, and the reaction of silatranes with functional copolymers. The obtained polymethacrylate copolymers were characterized using gel permeation chromatography, IR and NMR spectroscopy. It was shown that depending on the synthesis scheme used, polymers were obtained in the form of three-dimensional structures or soluble products. It was established that the molecular weight of the synthesized polymers depended significantly on both the content of silatrane fragments and the synthesis technique used. It was shown that the modification of linear carboxyl-containing copolymers by silatranes allows the synthesis of high-molecular polymers with a high content of silatrane fragments. For the synthesized polymers, thermal properties were investigated, and the hydrophobicity of the surface of polymer films was also evaluated. It was found that all the studied polymers did not have clear melting and crystallization temperatures. The polymers were stable in an inert atmosphere up to 270-280 °C, whereas in air they decomposed at lower temperatures with the restructuring of the macromolecular skeleton and the formation of highly heat-resistant silicone structures. An increase in the content of silatrane moieties in the copolymers led to an increase in the hydrophilicity of polymers.
It is well-known fact that water is a universal solvent due to its physicochemical properties and dielectric constant. Therefore, the majority of substances with a crystalline structure and the structure close to it are well soluble in water due to the dissociation of molecules into ions. Amino acids are organic ampholytes – substances capable of being in ionic forms in water. The quantitative and qualitative composition of ampholytes depends on the structure and composition of amino acids and pH of solution. The interaction of amino acid ions in solution with hydrogen ions and hydroxyl leads to the formation of complex cations and anions. The presence of amino and carboxyl groups in amino acid molecules contributes to the formation of inter-ion positively and negatively charged complexes which leads to the decrease in their mobility and electrical conductivity of solutions. It is observed with increasing concentration of amino acid solutions. The conductivity of amino acid solutions is also influenced by temperature which has a non-linear relationship. We have proposed the approach based on studying the effect of temperature on the equivalent electrical conductivity at infinite dilution λ∞ and describing the experimental data λ∞(Т) by the exponential Arrhenius equation. This article studies the possibility of describing the experimental data λ∞(Т) for aqueous solutions of a number of amino acids by this equation. It is shown that the Arrhenius equation with the found activation energy values adequately describes the dependences of limiting equivalent conductivity on temperature for aqueous solutions of valine, leucine, isoleucine, threonine, lysine, methionine, phenylalanine, L-aspartic and D-aspartic acids, histidine, arginine.
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