Pyrene-based monomer-excimer dual response organosilicon polymer for selective detection of 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP)

The formation or destruction of pyrene excimer with strong emission change make it a versatile fluorophore to construct excimer emission-based fluorescence probes for various analytes detection. The distinct difference between...

STUDY OF DEFORMATION PROPERTIES OF COMPOSITES WITH A HYBRID MATRIX BY THE METHOD OF DYNAMIC AND MECHANICAL ANALYSIS

Polymer and composite materials (PCMs) are widely used in various industries for production of small but complex parts and large-sized body parts subjected to significant loads. The production of more critical parts from PCM has led to the need to develop new compositions, structures and technologies for molding composites. The manufacturing technology of PCMs with a hybrid matrix is presented, one of the components of which retains its "liquid" state after the molding of the products, and the second is completely solid. In the resulting composite, the “liquid” components form an independent phase and together with the main binder material, the PCMs represent a hybrid matrix. The results of dynamic mechanical analysis (DMA) of basalt plastics with hybrid matrices, in which the composition of the “liquid” component are anaerobic technical wax and organosilicon polymer materials, are presented. DMA is performed on samples of two types: № 1 - samples with a low content of "liquid" components in the matrix and № 2 - samples with a high content of "liquid" components in the matrix. According to the results of the tests carried out, the best characteristics among PCMs with various types of hybrid matrices are possessed by samples with an organosilicon polymer material in the matrix

Effect determination of operating environments on growth of subfilm corrosion of machine parts with dispersion-filled polymer coatings

Detection methods of subfilm corrosion as well as the effect of operating environments on the corrosion growth rate have been examined. The study results of the effect of operating environments on parts with organosilicon polymer coatings modified with various dispersed fillers are presented. It is shown that the addition of mica into the composition of an organosilicon coating make possible to have a protective anticorrosion coating with good adhesion to the metal surface. The effect of operating environments on wettability of the polymer coating surface is described.

Creation of Basalt Plastics with Different Types of Hybrid Matrices

Basalt plastic, thanks to its complex of valuable operational properties, has a potential variety of applications. the article describes the technology of production of basalt plastics with various types of hybrid matrices, one of the components of which is cured in the molding process, and the second-like a binder in natural materials, retains its viscoelastic state. The viscoelastic component makes it possible to increase the deformation properties in the zones of their location, preventing cracking under increased loads. As a result of the conducted mechanical tensile tests, the average values of absolute breaking forces, tensile strength and elongation during fracture of basalt plastic samples with different types of hybrid matrices were obtained. The addition of viscoelastic components (such as technical wax, anaerobic, and organosilicon polymer materials) to the basalt plastic matrix allows to increase the elongation at fracture by 2...5%. Anaerobic polymer material in the basalt plastic matrix allows to increase the tensile strength of the composite material, as well as significantly reduce the dispersion of the measured values. This provides an effective prediction of the operational properties of the structural material in the design of products. On the basis of microanalysis of the structure of basalt plastics with different types of hybrid matrices, an explanation of the causes of changes in the mechanical properties of the resulting composite materials is given.

TEST METHODS FOR POLYORGANOSILOXANE COMPOSITIONS USED AS PROTECTIVE COATINGS IN ELECTRONIC INSTRUMENTATION

Представлен обзор по методам испытаний кремний органических полимерных композиций, применяемых в качестве защитных покрытий в современном электронном приборостроении. A review is given of testing methods for organosilicon polymer compositions used as protective coatings in modern electronic instrumentation.

Internal Cylindrical Grinding Process of INCONEL® Alloy 600 Using Grinding Wheels with Sol–Gel Alumina and a Synthetic Organosilicon Polymer-Based Impregnate

The development of modern jet engines would not be possible without dynamically developed nickel–chromium-based superalloys, such as INCONEL® The effective abrasive machining of above materials brings with it many problems and challenges, such as intensive clogging of the grinding wheel active surface (GWAS). This extremely unfavorable effect causes a reduction in the cutting ability of the abrasive tool as well as increase to grinding forces and friction in the whole process. The authors of this work demonstrate that introduction of a synthetic organosilicon polymer-based impregnating substance to the GWAS can significantly improve the effects of carrying out the abrasive process of hard-to-cut materials. Experimental studies were carried out on a set of a silicon-treated small-sized sol–gel alumina 1-35×10×10-SG/F46G10VTO grinding wheels. The set contained abrasive tools after the internal cylindrical grinding process of INCONEL® alloy 600 rings and reference abrasive tools. The condition of the GWAS after the impregnation process was studied, including imaging and measurements of its microgeometry using confocal laser scanning microscopy (CLSM), microanalysis of its elemental distribution using energy dispersive X-ray fluorescence (EDXRF), and the influence of impregnation process on the grinding temperature using infrared thermography (IRT). The obtained results confirmed the correctness of introduction of the impregnating substance into the grinding wheel structure, and it was possible to obtain an abrasive tool with a recommended characteristic. The main favorable features of treated grinding wheel concerning the reduction of adhesion between the GWAS and grinding process products (limitation of the clogging phenomenon) as well as reduction of friction in the grinding process, which has a positive effect on the thermal conditions in the grinding zone.

Organosilicon polymer-derived ceramics: An overview

Polymer-derived ceramics (PDCs) strategy shows a great deal of advantages for the fabrication of advanced ceramics. Organosilicon polymers facilitate the shaping process and different silicon-based ceramics with controllable components can be fabricated by modifying organosilicon polymers or adding fillers. It is worth noting that silicate ceramics can also be fabricated from organosilicon polymers by the introduction of active fillers, which could react with the produced silica during pyrolysis. The organosilicon polymer-derived ceramics show many unique properties, which have attracted many attentions in various fields. This review summarizes the typical organosilicon polymers and the processing of organosilicon polymers to fabricate silicon-based ceramics, especially highlights the three-dimensional (3D) printing technique for shaping the organosilicon polymer- derived ceramics, which makes the possibility to fabricate silicon-based ceramics with complex structure. More importantly, the recent studies on fabricating typical non-oxide and silicate ceramics derived from organosilicon polymers and their biomedical applications are highlighted.