Polymer Science, Series D最新文献

The molecular weight distribution of modified amino-formaldehyde resins synthesized at various melamine- and carbamide-to-formaldehyde molar ratios and catalyst modifier and diethylene glycol amounts was studied. Chromatograms of the obtained amino-formaldehyde resins are presented.

Professor V.A. Dodonov created, based on a complex of an organoboron compound with an amine, a two-pack aerobically curing adhesive capable of gluing polymers with low surface energy (polyethylene, polypropylene, polyvinyl chloride, Teflon) at room temperature. The trialkylborane-amine complex, when exposed to acid, releases R₃B, which is oxidized by oxygen and causes radical polymerization of the monomeric acrylate base and grafting to the surface of the polymers.

The review summarizes studies on modification of fish collagen and pectin to obtain the branched and three-dimensional structures. They are biodegradable and biocompatible sealants prepared via radical graft copolymerization under photocatalysis in the presence of a RbTe_1.5W_0.5O₆ complex oxide of a β-pyrochlore structure, including the variation of composition of a initial reaction mixture, and via the isolation stage by introduction of known modification additives.

This work is related to the study of the strength and radiation resistance of a new hybrid material made from basalt fibers and carbon threads. Products in the form of cylindrical rods can be successfully used as external fixation systems for injured limbs. The material under study has the property of radiotransparency, which makes it possible to easily carry out radiographic studies. Various mechanical tests were carried out on samples pre-exposed to γ irradiation over a wide dose range in an open atmosphere.

The results of experiments aimed at studying the dependence of the adhesion strength of a coating deposited onto a screw-shaped surface of a part through plasma spraying depending on technological spraying modes. Results of correlation and regression analyzes are presented.

As a result of the interaction of melamine and boric acid in an alcohol solution, complex salts containing one, two, and three acid molecules have been obtained. The resulting salts were introduced into the polypropylene melt, and the fire resistance and physicomechanical properties of the resulting composites have been studied. It is found that the introduction of these salts into polypropylene leads to an increase in the fire resistance of the original polymer. At the same time, in terms of heat resistance, manufacturability,. and rigidity, the composites are not inferior to the original polymer.

This article is a continuation of a series of articles on welding parts made of polymer composite materials based on thermoplastics. Methods for welding plastics based on thermoplastics with the conversion of various types of energy into heat and their classification are considered. The features of friction welding, ultrasonic welding, high-frequency welding, and radiation welding technologies are given. The main parameters of technological modes of the considered welding methods, areas of their use, and advantages and disadvantages are determined.

A model of the effect of an abrasive-liquid jet on a material sample and its experimental verification have been developed. Data from an experimental study on calculating the number of points of interaction between particles of an abrasive-liquid ultrajet and a sample are presented, as are comparative results of the staged experiment and probabilistic modeling data. The correlation coefficient of the collision coordinate values of the order of R = 0.97 was calculated. It is shown that the developed model for the distribution of interaction points of high-speed particles over the surface of a sample makes it possible to predict with sufficient accuracy the distribution of their coordinates over the surface area under consideration. The use of the model will make it possible to set the required value of abrasive concentration and other technological parameters, reducing the time for preparing experiments to diagnose the quality of paint and varnish coatings.

The viscoelastic properties of epoxy polymers modified with hexagonal boron nitride are studied in this work. The calculated elastic modulus is compared with its experimental value. It was found that boron nitride does not significantly influence the glass transition temperature of epoxy polymers.

An experimental assessment results of residual stresses magnitude, which was carried out using the cantilever method using plates made of carbon, glass, and basalt plastics as elastic substrates, are presented. The same type of epoxy binder was used in the fabrication of samples and in the fabrication of an elastic substrates. This work shows the dependence of the residual stress values on the curing mode. It was found that the residual stresses for basalt plastics are lower than those for glass and carbon plastics and that they are characterized by a lower relaxation rate.