Polymer Science, Series D最新文献

The review presents the production, properties, and application of new fire retardants for reducing the flammability of composite materials based on condensation polymers. The properties of composite materials based on epoxy resins are considered primarily, as they are the most popular and possess a range of valuable properties. It is shown that one promising area of research is the search for synergistic effects of reducing flammability and fire protection through the use of fire retardants based on precursors of various natures.

Nonhardening sealants are used at refrigeration equipment manufacturing plants for temporary sealing of structures during assembly. The paper studies the properties of highly filled sealing compositions based on low-molecular polyisobutylene grade PB-1300 (with a polymer binder content of 10–15%) intended for temporary sealing of refrigeration equipment. It is shown that, in a certain concentration range, an increase in the filler content leads to an increase in strength. A necessary component of highly filled compositions based on a nonpolar oligomer and a polar filler is a compatibilizer, in this case, stearic acid. It is found that petrolatum can be used to regulate the properties of compositions under study, primarily their viscosity properties. However, it should be taken into account that its introduction leads to deterioration of the physical and mechanical properties of compositions. These studies are of scientific and practical interest to developers and manufacturers of nonhardening highly filled sealing materials.

The article discusses surface modification of 09Mn2Si steel consisting of zinc coating followed by nitriding. Metallographic studies reveal the structure of a diffusion layer under zinc coating that consists of a transition area and an internal nitriding area. A positive effect of nitriding on coating adhesion to a steel substrate is demonstrated. An increase in the wear resistance of the nitrided coating and corrosion resistance in a salt medium is observed.

The effect of storage under different conditions on contact and adhesion characteristics was studied for plasma modified films from commercial aliphatic polyketone Poketon™. The films were stored at room temperature and normal pressure in a humidity chamber and after isothermal heating. The change in the wettability, surface energy, and its polar and dispersion components was studied. Data on the retention of these parameters under different storage conditions were obtained, and the change in adhesion properties (peel strength) was estimated by using Scotch®810 adhesive tape.

This work is devoted to the development and study of properties of composite protective coatings based on modified chlorosulfonated polyethylene. Formulations of compositions have been developed, the influence of additives and cross-linking agents of various chemical nature on technological and operational properties of polymer, as well as on resistance to atmospheric factors, has been studied.

Based on potassium salt of silicic acid (liquid glass) and hardeners of various types and compositions, “soft” conditions for curing and molding syntactic materials have been developed. The mechanical properties of three types of materials have been determined: a sheet material reinforced and filled with glass microspheres, a binder filled with glass spheres, and a sandwich material of a given thickness with a density of 0.63–0.82 g/cm³ obtained on their basis. A correlation is shown between the strength of the facing sheet material and the strength of the sandwich material.

The curing process of an ED-20 epoxy resin with AF-2 aminophenol and L-18 aminoamide hardeners and their composition in the presence of an oligosiloxane modifier is studied by differential thermal analysis. It is found that introducing an oligosiloxane modifier in the amount of 10 wt pts per 100 wt pts of ED-20 has no effect on the temperature range of the curing process for all the studied compositions. The use of an oligosiloxane modifier and a composition of hardeners makes it possible to obtain epoxy polymers with high bending strength and adhesion strength to a metal substrate (St3).

The method of pulsed mechanical action leading to a rheological explosion and radio frequency response has been used to study epoxy–anhydride compounds filled with micro glass balls, quartz powder, and basalt powder. It is shown that filling the compound with micro glass spheres has an advantage in impact-strength properties compared to filling with quartz and basalt powders. The obtained data on the radiofrequency response to impact and on the relaxation of elastic energy can be used to select compositions of epoxy-anhydride compounds for targeted use in the design of structural materials, such as high-voltage power-transmission and -distribution systems and protective coatings for civil facilities.

Polymer materials based on an unsaturated polyketone and chlorine-containing epoxy oligomers were created, and their mechanical, sorption, and structural characteristics were studied.

The paper shows that an abrasion-resistant dispersed composite on the base of epoxy resin with sand filler might be applied to identify both the wear specifics and the wear geometry, and as a protective (reinforcing) material, while its resistance to abrasive wear is mainly governed by the soil mass pressure.