Fibre Chemistry最新文献

The structure of technical felt before and after impregnation with an aqueous dispersion of synthetic latex was analyzed. Its physicomechanical property parameters were determined. The degree of influence of the amount of binder in the felt cloth on the parameters characterizing its shape stability was found.

The effects of treatment regimes on the mechanical properties of nonwoven needlepunch fabrics based on a blend of poly(ethylene terephthalate) fibers of linear density 0.33 and 1.7 tex and bicomponent fibers of 0.44 tex were studied. The stretching mechanism of various fabric compositions and the effect of adding fibers of higher linear density on structure formation and the mechanical properties of the fabrics were examined. The parameters for evaluating the stretching resistance, which occurred in two stages, were found. Materials with increased stretching resistance and unchanged tensile strength were obtained.

Low-temperature oxidation in air of domestic poly-p-aramid complex threads based on poly(p-phenylene terephthalamide), i.e., terlon, Rusar, and Rusar NT, that were nitrated beforehand by nitrogen dioxide was studied comprehensively by EPR and IR spectroscopy, thermoanalytical methods (TA, TMA), and scanning electron microscopy (SEM). Mechanisms of nitration and destruction of poly-p-aramid complex threads were proposed. The nitrosyl nitrate form of nitrogen dioxide was proposed as the oxidation initiator. The polymers were destroyed by degradation of N-nitrosoamides, N-nitrocompounds, and N- nitrites, i.e., nitration products of terlon, the main component of the thread. IR spectroscopy found that the major products of aramid thread nitration were esters and carboxylic acids.

The effects of the formulation and technological parameters on needleless electrospinning of Akvapol® polyurethane dispersions modified by solutions of hydrophilic polymers were studied to create nonwoven membrane materials.

To develop and implement reinforcing fibers of small diameter (less than 15 μm) and an elastic modulus exceeding 50 GPa, it is necessary to determine their mechanical properties. However, most of the conventional methods are challenging to apply to such objects due to the scale effect of the gauge length (distance between grips) on the static modulus when measuring fiber deformation by moving the grips (crosshead movement). This paper examines several advanced high-modulus fibers, including Twaron and Armos, along with introducing a model for calculating real modulus from measured values. To validate the model, experimental tests were carried out for several aramid fibers.

This work focuses on upgrading a device for the determination and control of physical and mechanical parameters, including the deformation properties, of fibrous materials. The modifications involve implementing the functionality of a tensile testing machine, as well as the ability to simulate complex deformation zones within controlled electrical systems of technological equipment in laboratory conditions.

The article analyzes the factors involved in making polyoxadiazole fiber-forming systems through spinneret capillaries under dry-wet method conditions. The drawbacks of the wet polyoxadiazole fiber forming method were identified. A method of two-stage extrusion of solutions of polyoxadiazole fiber-forming systems, the first of which is carried out through spinneret holes into a gaseous medium and the second, in a precipitating dilute sulfuric acid bath, is proposed. A mathematical interpretation of the technological factors of polymer solution flow through spinneret capillaries, including the rate of solution flow through capillaries with different diameters and spinneret drafting, is offered.

Changes in the strength of a one-dimensional elementary composite material−microplastic based on epoxide resin and complex aramid thread treated with graphene oxide are reported. The maximum increase in the strength of the microplastic was 13.36% and from 5.511 to 6.247 GPa. The graphene oxide concentration in the starting suspension for this was 0.0625 g/L.

The phenomenon of gel formation for the process of chemical fiber making from polymer solution was studied. An approximate algebraic equation of dependence of full gel formation time on precipitant concentration in the bath, precipitant content in the polymer solution, temperature of the solution in the bath, and radius of the polymer solution jet was derived. The dependencies obtained by modeling agree well with the results of calculations using a more comprehensive model of the gel formation process. Applicability of the derived equations for describing the gel formation phenomenon is shown.

The sorption mechanism of cadmium ions is studied using isolated fractions of microgel and pectic substances from pomelo albedo, beet pulp, and sunflower calathides. The sorption capacity of pectic polysaccharides, degree of sorbent affinity for the sorbate, and their binding strength are evaluated. The sorption process is found to obey the Langmuir equation. The thermodynamic parameters of the sorption processes at temperatures from 298.15 to 318.15 K are evaluated. The sorption process is found to have an exothermic mixed character.