Polymer Science, Series D最新文献

The paper considers a new type of shape fixing in special sewing products using pads manufactured by additive technology from modern plastics. The authors analyzed the properties of frame parts made by 3D printing and their budget analogues molded from polymer bandages. The experiment has been carried out on the example of sewing products designed to fix scanning sensors on the body of subjects. The prospects of the new padding material are justified by its low weight, high air permeability, strength, and adjustable rigidity.

The paper presents a technology for impregnating mammoth tusk (MT) fragments of grades III–IV with polymer resins to obtain high-quality blanks for the manufacture of souvenirs using milling on a CNC machine. It has been shown that alternating stages of vacuuming with the stage of holding the sample under increased pressure is an effective method for obtaining high-quality blanks from grade III MT. In addition to vacuuming/holding under pressure, heat treatment must be performed to obtain high-quality blanks from grade IV MT.

The paper considers the influence of annealing temperature on the properties of low-carbon powder steel. It is shown that, after high-temperature annealing, a significant amount of defects are eliminated, both ductility and strength increase, and the properties of powder steels become comparable to the properties of conventional steels. The effect of holding time and annealing temperature on the properties of low-carbon powder steel is considered. A noticeable improvement in the properties is observed after annealing for 60 min. It is shown that rapid cooling after hot stamping ensures the formation of a supersaturated solid solution, and so hardening is not a mandatory operation for such materials.

Modification of the epoxy diane resin ED-20 with 1.5 wt % copper(II) hydroxide–orthophosphate solutions (4 : 2 : 2) in phosphorous acid and in a mixture H₃PO₄ : (NH₄)₂HPO₄ = 10 : 1 (wt) and curing with triethylenetetramine results in the formation of crystalline phase of different structure and geometry but close chemical composition in the polymer. At the maximum modifier content 8 wt % the synthesized polymers are characterized by oxygen index values of 24.7–25.1 vol %. In addition, these polymers reach the category of resistance to burning PV-0 according to GOST 28157–89 (when the flame source is removed, the standard sample burns not more than 10 s and then independently extinguishes). The elastic modulus and bending breaking stress are 3.9 GPa and 53.3 MPa, respectively. The presence of ammonium hydrophosphate in the formulation leads to a decrease in initial viscosity values down to 48% and an increase in bending strength up to 2.5 times and heat resistance by 20–25°C.

The paper presents the results of mechanical (tension and interlayer shear) tests of basalt plastics and the results of experimental evaluation of residual stresses depending on the appret concentration and its application technology. As the apprets, we used 3-aminopropyltriethoxysilane solutions in concentrations from 0.1 to 5%. We discover that the appret in the concentration of 0.1–1% makes it possible to increase the strength of basalt-reinforced plastics under interlayer shear up to 25%, but this has in fact no effect on its tensile strength. Increasing the appret concentration insignificantly affects the mechanical properties of basalt plastics and the rheological properties of the binder. We prove experimentally that use of the appret caused an increase of the basalt plastics’ resistance to alkali solutions, as well as to distilled and seawater.

This article is devoted to the study of the possibility of using pipe-production waste—gas-cleaning dust—as polyfunctional modifiers of polychloroprene adhesives. The gas-cleaning dust microdispersed structure, the presence of a high content of silicon dioxide, and physicochemical activity made it possible to increase the adhesive properties and heat resistance of adhesive compositions based on polychloroprene.

Novel methacrylic monomers, quaternary ammonium compounds of various composition, which can be used to impart antibacterial and fungicidal properties to polymers based on them, have been synthesized. The monomers with one quaternary nitrogen atom and ionene macromonomers based on methacrylic esters and amides containing several cationic groups in a substituent have been synthesized and investigated.

A technology was developed, and a new sorption material based on silicon dioxide was produced. The modified method to synthesize monodisperse silica particles as alcohol sols with subsequent sedimentation stage allows the production of monodisperse silica particles with ordered structures formed into a three-dimensional lattice. The block structures are packed via supercritical drying in an autoclave. This allows the material to transform into a vaporous aggregate state without the cavitation effect to form a supercritical fluid. Monodisperse silica spheres with identical dimensions were obtained after hardening the material under high temperatures and pressure. This determined their strength (Vickers hardness ≈100) and high porosity (≈33%). The sorption properties of the new material were tested during the purification of industrial wastewater from a process plant for processing industrial raw materials.

The influence of rosin content on the adhesion properties of filled compositions based on butadiene-nitrile rubber (BNR) and thiokol (to steel, duralumin, BNR-based rubber) was studied. Adhesion properties of model compositions based on BNR and compositions based on a BNR–thiokol mixture were estimated. It was found that the dependence of adhesive strength on rosin content in BNR-based compositions has an extreme character. It was shown that the adhesive strength of these compositions does not depend on the type of substrate or test method, which is typical for “pressure-sensitive” adhesives. It was shown that BNR-based compositions containing 5 pts wt of rosin have an optimal set of adhesive properties, and a further increase in the rosin content in the composition leads to a decrease in adhesive strength.

The influence of new fillers of natural origin on the deformation–strength and adhesive characteristics of ethylene–vinyl acetate copolymers and high-pressure polyethylene has been studied. It has been established that a carbon-mineral filler can be used as an adhesive-active filler of polyolefins. The efficiency of the carbon-mineral filler is somewhat higher than that of talc.