Том 50, № 5 (2019)

A synthesis has been developed for cellulose titanium oxide, an organic inorganic hybrid. The preparation of a hybrid was demonstrated by x-ray diffraction, water vapor adsorption, and measurement of photocatalytic activity.

The fundamental possibility of modifying polyacrylonitrile fiber fillers by chemical metallization was demonstrated. Technological regimes and electrolyte compositions for chemical silvering and coppering were selected. It was established that the obtained coatings on variously oxidized fibrous wastes from production of oxy-PAN are distinguished by good adhesion and high electrical characteristics and can be used for low-voltage electrical connections for the flexible conductors widely used in electrotechnology.

Work was done on filling thermosetting resin with various carbon fibers. The influence of the mechanical properties of the fibers, the mixing rate and the mass fraction of the fibers in the compound on the degree of their destruction during extrusion compounding was studied. It was found that when the elastic modulus of the fibers is increased 1.7–1.8 times, the average fiber length is decreased 2.4–4 times. Therefore, the degree of shredding increases. As the fiber feed rate increases, longer filaments are formed, which is also confirmed by comparative data on the average fiber length. A 10% increase in the mass fraction of fiber in the compound results in a 1.9-2.5-fold decrease in the average fiber length, which is explained by an increase in the number of episodes of contact interaction between the fibers.

We use computer modeling and the finite-element method to consider the influence of structural nonuniformity in warp yarns and the impact of weft yarns on strain and the stress state of the warp in fabrics.

A design of a device for winding wrapping bundle for forming composite armature rib is proposed. The design makes it possible to enhance the efficiency of the process line for production of composite armature by reducing the number of interruptions and production wastes and increasing the reliability of the mechanisms by reducing vibrations.

Atomic-force microscopy was used to visualize latex particles of polyfluoroalkylacrylates and to determine their sizes and particle-size distributions. The conditions for preparing samples for the studies and the operating mode of an NTEGRA Prima (NT-MDT) scanning probe microscope were determined.

The effects of length and concentration of carbon (CF) and glass fibers (GF) on the rheological, physicomechanical, and thermal properties of the high-temperature thermoplastic polyphenylene sulfone (PPSU) containing up to 40 wt% filler were studied. The fillers were CF and GF of lengths 0.2 and 3 mm. Addition of CF and GF decreased noticeably the melt flow index and PPSU impact viscosity so that the flowability limit disappeared in the stress—strain diagram because of the reduced ability of the material for plastic deformation. The elasticity modulus and strength of the composite for bending and tension increased with increasing fiber content. The heat resistance increased significantly with increasing CF content. Samples containing CF of length 0.2 mm had higher massloss temperatures. The heat resistance changed insignificantly for composites containing GF.

Present-day rheological theory for the flow of dilute, concentrated, and highly concentrated filled polymeric solutions and its experimental basis are considered. The optimum type of fiber-forming polymer and solvent for preparation of spinning compositions is chosen. The advantages and disadvantages of various grades of activated carbon for the formation of filled fibrous sorption-active materials are noted. It was found that the nature of the activated carbon (the method of preparation, type of feedstock, porous structure, etc.) has a significant effect on the stability of the suspensions. The principal factors that determine the rheological characteristics of spinning compositions, such as the viscosity of the dispersion medium, the nature of the fillers, and the volume fraction and dispersibility of the solid phase, were studied. Their optimum values and their quantitative contribution to the change of viscosity were also established.

We present experimental data on the strength of filaments in the para-aramid fiber Taparan for gage length 10, 20, 30, and 40 mm. A nonlinear multiplicative model is used to represent the relationship between the properties. The coefficients of the model are determined from experimental data. The critical length is calculated for a single filament in the Taparan fiber. The multiplicative model is used to predict the strength properties for filaments of critical length.

The tribological properties of multifilament aluminum oxide yarns were studied during frictional contact with submicro rough surfaces with known statistical roughness parameters. The tangential drag coefficient largely depends on roughness isotropy of the contact surfaces, the relative position of the asperities of the contacting surfaces and the nature of wetting of the surfaces with a sizing emulsion. The stability of the friction coefficient in the experiments of the first series with the arrangement of the yarns in the direction of sliding of the counterpart is higher than for the experiments of the second series when the yarns are at a 90° angle to the direction of sliding of the counterpart.

Air permeability of multilayer nonwoven fabrics obtained by combining needle punched webs made from fibers with different linear mass densities is investigated. The optimal composition of nonwoven webs providing multilayer fabrics with increased permeability is determined. A model linking the air permeability of multilayer fabrics with their thickness, which depends on the number of layered webs, is proposed. The air filtration mechanism in webs and multilayer fabrics is substantiated. The process of structural formation of the webs and multilayer fabrics is considered. The influence of the structure of the webs and multilayer fabrics on their air permeability is determined.

We describe mathematical modeling and comparative analysis methods for the deformation/recovery properties and shrinkage of aramid textile materials. We have studied the micromechanisms for such a phenomenon as shrinkage of polymer materials.

The merits of the aerodynamic technique of producing fibre cloths and their characteristics in terms of various physical quantities that affect the quality of textile materials are analyzed. The demerits of the aerodynamic technique are identified and the optimum technical solution for their elimination is proposed. The characteristic equation of fibre motion in the chamber and the transfer function of the aerodynamic chamber are presented. The stability range of the studied control object and the quality of the transient process in the textile materials formation system are determined and the characteristic graphs are constructed.

New composites are obtained in the diffusion-adsorption immobilization of electron-excess zinc(II) 1,10-phenanthrocyanine complexes [(phen)_nZn(μ-phencyanine)Zn(phen)_n(OAc)₄∙HOAc] (n = 0-2) in a 3D structure of super-swelling cellulose hydrogels. A mechanism is proposed for the immobilization of the zinc complexes in the hydrogel structure. The functional and chemical composition of the composites was studied in detail using Fourier transform IR spectroscopy. The immobilization of the complexes in the hydrogels structure was found to lead to their chemical reaction with cellulose in the hydrogel matrix.