Fibre Chemistry最新文献

We describe approaches to the construction of mathematical models of relaxation processes occurring in industrial-use polymer textile materials. The problem of constructing mathematical models that are most appropriately suited to the processes being modeled is solved.

The relevance of developing and refining methods for computational prediction of the stress-strain state of polymer materials under the action of non-destructive mechanical stresses is associated with the increasing industrial application of such materials. In addition, these methods can be used when conducting a comparative analysis of various materials and investigating relationships between their properties and structure, as well as for a purposeful in-process monitoring of material properties and prediction of the results of short-term and long-term mechanical stresses. Time-spectral modeling of the viscoelastic behavior of polymer textile materials is important in terms of determining the functional and operational characteristics of materials, thus enhancing their competitiveness.

Nonwoven microfibrous materials were electrospun from polystyrene solutions of concentrations 15-25 wt% in various solvents (DMF, THF, CHCl₃, and EtOAc). Scanning electron microscopy found that fibers of various morphologies, both round and ribbonlike, with smooth and porous surfaces could be produced depending on the spinning solution parameters and process conditions. The average fiber diameter could be regulated in the range 0.5-20 μm. Addition to the spinning solutions of EtOH was shown to improve their rheological and electrophysical characteristics, to decrease the average diameter of the resulting fibers, and to improve their homogeneity. The obtained materials demonstrated superhydrophobic properties and high sorption capacity (up to 185 g/g) for motor and silicone oils. This enabled them to be considered effective sorbents for remediating spills of oil products from water surfaces.

The methods of mathematical modeling for describing the creep behavior of industrial-use polymer textile materials are presented. The problem of constructing mathematical models that most adequately correspond to the processes under modeling is given.

The sorption mechanism of Cd²⁺ and Pb²⁺ by edible fibers, namely isolated highly purified fractions of pectinic polysaccharides of pomelo albedo, beet pulp, and sunflower calathides, was studied. The Lagergren and Ho-McKay equations were used to evaluate the contribution of a chemical reaction to the sorption process. A relationship was found between the sorption capacity of pectinic polysaccharides and the concentration of free galacturonic acids.

The effects of physical fields on extraction of sodium hydroxide from cellulose fibrous materials were studied. Data on the equilibrium during sorption and desorption of sodium hydroxide by cotton cloth were analyzed. The choice of physical field as enhancer was justified. The kinetic coefficients in extraction with various enhancing effects were shown to change.

Prediction of relaxation processes of textile elastomers used in implantology and of the polymer fibers formed therefrom is based on mathematical modeling of relaxation processes with due account of experimental data. Construction of mathematical models of relaxation processes of these materials with due account of short-term experiment makes it possible to select a single solution from the wide diversity of possible solutions.

The influence of various factors on fibrous canvas during its movement in the cooling section of the Lap FormAir technological line and the action of the forces on the canvas from the calender side during its formation were studied. A differential relationship among the initial fibrous material flow section area, the conditions of operation of the final calender, and the output geometrical parameters of the finished fabric was established. Mathematical equations that allow determination of the geometrical parameters of the nonwovens were derived.

We present a computational method for estimating the average values of heat and mass transfer processes in a heat exchanger for use in engineering calculation methods. The formula obtained for calculating a heat exchanger is transformed to obtain a criterion dependence, which simplifies application of this formula.

This work investigates the influence of fabric and bulk densities of needle-punched nonwovens on the perpendicular orientation of fibers to the fabric surface obtained during needle punching. By using the proposed model with the permeability coefficient and fabric parameters, a coefficient reflecting the number of fibers oriented in the direction of airflow in the nonwoven is calculated. It is established that the coefficient in the model depends on the fabric density, varying among nonwovens having different bulk densities. A model was developed to predict the proportion of fibers oriented in the direction of airflow and, consequently, the permeability coefficient of the nonwovens. It is shown that the model is limited by the fabric and the bulk densities.