卷 51, 编号 3 (2019)

The solution of various applied problems usually leads to the need to find answers to purely scientific fundamental questions and discover new phenomena. The article gives examples of such discoveries. It was discovered that flammability of polymeric materials can be decreased by dispersion of a material containing microencapsulated low-boiling flame retardants on exposure to an external fire source. The composition of the Earth’s atmosphere is analyzed in terms of dynamic equilibrium of the processes of oxygen production from forests and the consumption for their combustion during fires. The study of the amazing kinetics of the preparation of polyformaldehyde from formaldehyde and its cyclic trimer, trioxane, was explained, firstly, in the creation of the theory of reversible heterogeneous polymerization of trioxane and led to a fundamentally new, thermodynamic, method of regulating the molecular and supramolecular structure of the polymer. Secondly, on the example of polymerization of formaldehyde, a possible advantage of “diffusion” over “kinetic” modes was discovered. A similar effect was confirmed for the process of sulfuric acid alkylation of high-octane gasoline production.

The change in relaxation state of polymer components of wood during its high-temperature biorefining and extrusion briquetting and subsequent heating at 380-450°C, i.e., above the thermal decomposition temperature of wood, is analyzed. It is demonstrated that the system can be translated into brittle state by changing the moisture content of the wood and treatment temperature and into forced plastic state by subsequent moistening, heating, and compression-shearing. Carbonization and activation of charcoal briquettes can be combined by subsequent low-temperature pyrolysis in controlled vaporgas environment conditions.

Fibers of bacterial cellulose were obtained for the first time from solutions in N-methylmorpholine N-oxide (NMMO) by using the concept of solid-phase dissolution of bacterial cellulose. The mechanism of solid-phase dissolution of bacterial cellulose in NMMO is examined with due regard to the structural and morphological characteristics of native bacterial cellulose. By investigating the structure of the fibers it was possible to reveal the different orientation of the main diffraction planes of the outer shell and inner part of the fiber reflecting the structural aspect of the shell–core morphology. The fibrillar morphology of the fiber was established by scanning electron microscopy. The thermal characteristics of the fibers of bacterial cellulose differ radically from the characteristics of fibers of plant origin in the preponderance of condensation processes that produce exo effects on the thermograms and lead to increase of the carbon residue. The mechanical characteristics of the obtained fibers were characterized.

Electrospinning of fibrous bandage material based on poly(vinyl alcohol) containing CeO₂ nanoparticles was investigated. Medical and biological effects of Ce compounds on post-burn scartissue deformation were assessed experimentally. The release kinetics of nanoparticles from the fibrous material were studied. The results demonstrated that use of fibrous materials containing CeO₂ nanoparticles (1%) as wound dressings was promising.

Information on industrial paper obtained from special purpose heat-resistant and fire-resistant fibers by the method of fiber swelling is presented. Results of a study of the effect of fiber cutting length on the mechanical properties the paper are presented. Corresponding dependencies are established.

The technological foundation for producing high-porosity fibre material with increased tensile strength is developed using the results of investigation of the mechanism of stretching of needlepunched nonwovens. The current methods of treatment of needlepunched materials are analyzed and they are shown to be not effective enough for producing high-porosity materials. A compounding and technological approach is developed for producing high-porosity materials with improved tensile strength.

A correlation is established between ultimate uniaxial tensile strength and abrasion resistance of footing thermoelastic plastics (thermoplastic elastomers). In this regard, the parameters of properties of materials of various manufacturers and parties known from literature sources and results of investigations by these authors are analyzed. A mathematical model is constructed, which enables determination of abrasion resistance of thermoelastic plastics from the ultimate uniaxial tensile strength values with an accuracy well enough for practical estimation.