THE CONCEPT OF MULTI-LEVEL MODIFICATION IN THE TECHNOLOGY OF HIGHLY FILLED FLUOROCOMPOSITES

The structural and technological aspects of obtaining composite materials based on polytetrafluoroethylene are considered. It is shown that due to the existence of inert components in the process of interfacial interaction with the degree of filling in the traditional technological paradigm implemented, structural paradox manifests itself in proportion to the reduction of the parameter of tensile strength with increasing degree of filling. According to the concept of multi-level modification, the technological principles are proposed to eliminate the negative impact of the structural paradox fluorine composites by controlling the structure of the organization at various levels – molecular, supramolecular, and interfacial phase. Efficient methods of manufacture of products from highly filled fluorine composites containing 25–35 wt. % carbon fiber with parameters of deformation and strength characteristics higher than the corresponding parameters of analogs.

Experimental Study on Coupling Influence of Temperature and Confining Pressure to Deformation and Strength Characteristics of Rock-like Material with Pre-Existing Crack

In this paper, destructive compression tests under the coupled influence of temperatures (20–60 °C) and confining pressures (0–7 MPa) were carried out on rock-like material with pre-existing crack to explore the deformation and strength characteristics. The stress–strain curves of rock-like material under the coupled influence of temperatures and confining pressures were obtained. Meanwhile, the correlations of peak stress, peak strain, and average Young’s modulus with temperatures and confining pressures were obtained. The results of the experiments indicate that, firstly, the compressive strength decreased and the deformation increased due to the influence of pre-existing cracks; the combined effect of initial cracks, temperature, and confining pressure gave rise to a more complicated mechanism of soft rock deformation. Secondly, the deformation of rock-like material was affected by initial cracks, confining pressures, and temperatures, but the influence of temperature was lower than that of confining pressure and initial crack. The failure mode of rock-like material was brittle at the confining pressure of 0 and 1 MPa and plastic at the confining pressure of 5 and 7 MPa. The critical confining pressure value of failure mode for rock-like material was 3 MPa. Thirdly, the peak strength and peak strain of rock-like material increased with confining pressure. Temperature had less influence on the rock-like material strength and peak strain than confining pressure. Lastly, Young’s modulus decreased with temperature and confining pressure.

Investigation of the deformation and strength characteristics of the thread connection in the manufacture of products from fur waste

By the method of mathematical planning of the experiment, regression equations were obtained for the breaking load and the breaking relative elongation of the thread connection of a special furrier’s seam in the manufacture of products from fur waste. As input factors were taken: the number of stitches in 1 cm., Thread thickness, needle diameter. The features of the behavior of the strength model of this thread connection are revealed.

Deformation and Strength Characteristics for the Calculation of Structures Based on Fiber-Reinforced Concrete Composites

Currently, there is a steady increase in the production of reinforced concrete structures in factory and construction site conditions for various types of modern buildings with higher operational requirements for them. These structures are pre-calculated according to complex design schemes of loading which also leads to increased requirements for the materials used. One of the ways to solve a number of these problems is the use of fiber-reinforced concretes, but for this it is necessary to experimentally identify the deformation and strength characteristics of dispersed reinforced concretes and take it into account when calculating structures. A scientific team of the Institute of New Materials and Technologies of the Ural Federal University is engaged in solving of this research task, which will expand a number of construction opportunities while maintaining economic feasibility in the future.

Study of operating properties of aanticorrosion packing papers

Metal products are subjected to atmospheric corrosion during transportation and storing. An important way to prevent this negative phenomenon is application of special packing materials, in particular materials, containing volatile inhibitors of corrosion, which protect metal against various corrosion agents. To protect metal effectively it is necessary to provide a definite level of operating characteristics of packing materials. The purpose of the work was the study of operating properties of inhibited crepe, inhibited and laminated polyethylene film, inhibited crepe and reinforced by polypropylene web papers, manufactured by OJSC “PP TechnoKhim”, Magnitogorsk, used for packing of metals. Structural and dimensional, sorption, deformation and strength characteristics, of the studied anticorrosion papers are presented, the characteristics being calculated based on the results of measurements. To determine their physical-mechanical and anticorrosion properties, standard methods and methodologies were used. To evaluate impact of moisture and transportation conditions, indices of water adsorption and wear of the studied papers were determined. Inhibitor content in these materials was determined by thermogravimetric analysis method. Their protective ability was studied on samples of low carbon steel strip. For accelerated corrosion tests the strip samples were degreased by alcohol, dried in air and packed in the studied anticorrosion papers, after that they were exposed under increased temperatures and moisture conditions. It was determined, that among the materials under the study, the inhibited crepe paper, reinforced by polypropylene web, hhas the best complex of physical-mechanical and anticorrosion properties. It provides a higher level of prevention corrosion of metal l and surpasses other materials in a number of deformation and strength characteristics. Recommendations were proposed to improve qquality of produced anticorrosion papers.