Polymer Science, Series D最新文献

The fatigue characteristics of BND 60/90 grade bitumen, asphalt mastic (AM), modified bitumen (MB), and ternary mixtures (bitumen–filler–modifier) (modified asphalt mastic (MAM)) have been studied. Mineral powder (MP) with a bitumen : MP ratio of 2 : 1 and 1 : 1 has been used as a filler in AM and MAM. Active powder of discretely devulcanized rubber (APDDR) obtained by means of high-temperature shear grinding was used as a modifier in MB and MAM in an amount of 12.5% of APDDR with respect to the weight of bitumen. The positive effect of APDDR exerted on the fatigue life of bitumen and asphalt mastic has been shown. Such fatigue parameters as postpeak pitch angle and τ_max/({{gamma }_{{{{tau }_{{{text{max}}}}}}}}) determined from τ(γ) curves in a linear amplitude sweep test are promising for the ranking of modified samples containing a network of bonds.

The results of studies concerning the effect of ultrasonic oscillations on the contact angle between glue and substrates made of 45 grade steel and of a VT-3 titanium alloy are presented. A change in the contact angle and the lifting height of the glue column in the capillary has been determined depending on the amplitude of oscillations of the ultrasonic emitter end. The decrease in the contact angle affected by oscillations amounts up to 25°, whereas the capillary effect exhibits a more than 14-fold increase. The obtained effects are described depending on a treatment mode.

The destruction features of porous materials are considered. The main types of destruction characterizing powder materials are shown. A diagram of interparticle contact loaded by an external force is presented and the effect of porosity exerted on the destruction mechanism is considered.

This paper discusses main characteristics and features of the use of metal perforated foils and metal knitted and knitted–soldered wire meshes in the creation of effective lightning-protection systems for carbon composite structures.

A review of patent and technical literature in the area of publication of adhesives for gluing polar and nonpolar rubbers with metals during the vulcanization process has been presented. Information on the original components that are used in the production of the adhesives of this class (rubbers, modifiers, vulcanizing agents, accelerators of the vulcanization process, fillers, solvents) is presented. Basic properties of adhesive joints made with the use of the adhesives for this purpose have been reviewed.

Studies of structure formation of modified impregnating amino-formaldehyde resins are considered. Based on the obtained deformation curves of cured impregnating amino-formaldehyde resins, the elasticity modulus, slow elastic deformation and the elasticity equilibrium modulus of resins were calculated. Based on these calculations, the dependences of these indicators on time were constructed. It has been shown that modification of amino-formaldehyde resins improves the rheological properties of impregnating amino-formaldehyde resins.

The paper describes the steps of development of single-component polyurethane sealants, an area being developed at the Department of Synthetic Rubber Technology.

The results of experimental studies of impact strength and tensile strength of carbon-fiber-reinforced plastics with a two-phase reinforcement scheme, including those exposed to negative temperatures (–30 and –50°C), have been presented. A feature of the tested carbon-fiber plastic samples is the presence of an additional reinforcing material in their structure (material of the “liquid” phase), which is a monomer or polymer and provides an increase in the relaxation characteristics of the composite. Triethylene glycol dimethacrylate, silicone sealant, and synthetic wax have been used as such materials.

An effect of an increase in the adhesion strength of aluminum–aluminum adhesive joints based on ethyl 2-cyanoacrylate and methoxyethyl 2-cyanoacrylate with additions of polymer para-dinitrosobenzene, 1,3,5-trinitrosobenzene, and 2,4,6-trichloronitrosobenzene is shown. This effect is associated with the formation of azomethine groups and additional intermolecular interactions in the adhesive joint.

The results of studies of the ultrasonic treatment of an epoxy glue on the properties of formed joints were presented. The tensile tests of glue joints between plates with different roughness were performed. The factors influencing the strength of formed joints depending on the ultrasonic treatment regime and the state of glued surfaces were established. A maximum increase in strength from 9.3 to 14.4 MPa was attained for the joint between the specimens subjected to sandblast finishing with the glue treated in the high-amplitude regime.