The paper studies the dynamic-mechanical characteristics of styrene-isoprene-styrene, polybutyl methacrylate, thermoplastic polyurethane block copolymers and their blends by dynamic mechanical analysis. It is found that blending of several types of polymers allows to extend the range of effective vibration absorption. A combination of polymers with high damping properties over a wide temperature-frequency range was determined. The influence of vibration frequency on dynamic-mechanical properties of composites has been investigated.
Keywords: polymer composite material, dynamic mechanical analysis, polybutyl methacrylate, thermoplastic polyurethane, styrene-isoprene-styrene block copolymer, vibration absorption, damping material, glass transition temperature
Vulcanization is a technological process that transforms plastic rubber into rubber. As a result of vulcanization, the shape of the product is fixed, and the material becomes more durable, hard and elastic. The purpose of the article is to determine the effect of octyl phenol-formaldehyde resin on the vulcanization parameters and to identify its optimal amount for the development of vibration-absorbing materials based on butyl rubber. The effect of a vulcanizing agent (octyl phenol formaldehyde resin) on the properties of the rubber compound during vulcanization was established. As a result of the study, the kinetics of vulcanization and the effect of various components on the properties of the rubber compound, such as elongation at break, conditional tensile strength and specific damping ability, were studied. This study is conducted in order to find the optimal rubber for placement in a seismic damper used in buildings and structures.
Keywords: vulcanizing group, vibration absorbing material, butyl rubber, rubber compound, vulcanization, octyl phenol formaldehyde resin, seismic damper
The technological process of manufacturing self-adhesive radio-absorbing materials is considered. The technological mode of manufacturing radio-absorbing materials consists of two operations – the preparation of a mixture and the production of radio-absorbing materials from the resulting mixture. An important step is mixing the mixture. The quality of the radio-absorbing material depends on the quality of the mixture.
Keywords: mixture, mixing time, scanning probe microscope, microstructure study
Due to the increasing pace of construction and overhaul of roads, there is a need to introduce more economical and efficient technologies. One of such technologies is soil stabilization. Based on the study of various scientific literature and project documentation, typical soils of the foundation and roadbed of the Kirov region have been established, and their features have been identified. During the study of the soils of the region, several dangerous geological processes were discovered that affect the operation and construction of roads. The article analyzes various methods and techniques of stabilization of heaving soils, as well as possible design solutions for the construction of a layer of modified soil. In addition, the mechanisms by which stabilization is carried out and cases of their application were given. In the course of the study, the main types of stabilizing additives, their features and principle of operation were considered. In order to identify the degree of influence of various binders on the technological sequence of construction, variants of schemes for the production of work on soil reinforcement are presented, depending on their types. According to the results of the study, it was concluded that the stabilization technology is one of the most modern, efficient and cost-effective and provides various advantages in comparison with other alternative methods of strengthening of heaving soils. The relevance of this method for the Kirov region is also proved.
Keywords: road, construction, technology, stabilization, soils, additives, recycler, binders, soil cement, heaving, strengthening
This article is devoted to the problem of development of damping polymer materials with high damping properties in a wide temperature range. The purpose of this article is to study the loss factor and strength of polymer materials based on ethylene-vinyl acetate when additional polymers in the form of rubbers are added to them. The leading method to investigate this problem is the method of dynamic mechanical analysis, which allows to obtain information about changes in the dynamic properties of polymeric materials subjected to oscillating loads depending on frequency and temperature. According to established experimental dependences, it was possible to define the type of additional polymer expanding the temperature range of effective damping and increasing tensile strength of composites based on ethylene-vinyl acetate. The percentage content by volume of the additional polymer was established at which its efficiency on the dynamic and mechanical properties of composites on ethylene-vinyl acetate basis will be greatest.
Keywords: ethylene-vinyl acetate, polymer, chlorobutyl rubber, nitrile butadiene rubber, strength, damping, glass temperature, dynamic mechanical analysis