Investigation of the Process of Hardening of Diglycidyl Ether Bisphenol a by Phosphate Binders

The interaction between diglycidyl ether bisphenol A and conventional and waterdeficient phosphate binders has been investigated. The data of chemical analysis, IR spectroscopy, and differentialthermal analysis point to the formation of a spatially crosslinked epoxy polymer under the influence of the phosphate binders. It has been shown that conventional binders can be used as hightemperature hardeners of epoxy oligomers. When waterdeficient binders are used, the formation of a threedimensional polymer structure is observed at room temperature.     

Determining influence of the phase interface on the properties of compositions of phenylone with element-carbon fibers

Interphase processes in the compositions of aromatic polyamide phenylone with element-carbon fibers are studied. Significant differences in the structure and properties of polyamide discretely reinforced with metal-carbon fibers and carbon fibers with functional groups are revealed. It is found that the observed changes are mainly due to the physicochemical interaction on the interface “fibrous filler-polymer matrix” during formation of the composition. State Agrarian University, Dnepropetrovsk; Institute of General and Inorganic Chemistry, Belorussian Academy of Sciences, Minsk. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 35, No. 3, pp. 86–90, May–June, 1999.     

Piezoelectric effect in composite implants for replacement of bony tissue

We developed “IKVOBAN-U” composite polymer implants to replace defects in bony tissue and fill large bone cavities. The presence of piezoelectric properties in the developed implants whose parameters are close to those of biological objects is revealed. Tests carried out on animals and the use of model media showed that the piezoeffect is preserved after prolonged holding in these media.     

Influence of Ion-Beam Carbon-Fiber Surface Treatment on the Angle of Wetting by Epoxy Oligomers

The influence of the regimes of modification of carbon fibers by an argon ion beam on the change in the angle of their wetting by an epoxydiane oligomer has been investigated. It has been shown that ion-beam treatment of carbon fibers leads to a considerable decrease in the wetting angles (the difference between the wetting angles for nonmodified and modified fibers is up to 32.2–38.7°). Accordingly, there is also an increase in the value of the equilibrium work of adhesion by 36.2–41.6% in the contact zone. It has been established that ion-beam treatment of carbon fibers by argon ions leads to an increase in the shear strength when microplastics based on them are formed. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 3, pp. 104–107, May–June, 2005.     

Heat-insulating composite based on unwoven materials and organomineral binder

Composites based on unwoven cellulose-hydrate and carbon materials and an organomineral binder have been developed and investigated. Optimal compositions of the composites feature a higher fire resistance, a low density, and effective thermophysical characteristics. The composites are promising for use as heat-insulating materials with a rigid structure in different branches of the national economy and industry. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 1, pp. 85–91, January–February, 2009.     

Influence of an electric field on the hardening process and the properties of an epoxy composite discretely reinforced with phosphocarbon fibers

The influence of an electric field on the hardening process, the structure, and the properties of an epoxy composite in the presence of a phosphorus-containing carbon filler has been investigated. It has been shown that under the action of an electric field the process of formation of a three-dimensional epoxy polymer in the presence in the system of phosphocarbon fibers proceeds more intensively with the formation of a more rigidly bound structure of the polymer as compared to the same composition hardened in the absence of the field. It has been established that the fibrous filler-binder interface has a dominant role in the formation of a spatially cross-linked polymer and in the properties of the product hardened both under the action of the electric field and without it. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 3, pp. 47–54, May–June, 2007.     

Influence of carbon fibre on formation kinetics of crosslinked copolymer from bisphenol A dicyanate and epoxy oligomer

The influence of carbon fibre on the curing kinetics of the prepolymer based on bisphenol A cyanurate and epoxy resin has been studied using infra-red spectroscopy. It was found that the curing process of the prepolymer is very complicated. It is shown that in curing the prepolymer a number of the sequential transformations of one ring structure into others occurs. An introduction of the carbon fibre (CF) of two types, original CF and modified CF (MCF) containing phosphate groups, affects strongly the prepolymer curing. Both CF and MCF accelerate the conversion rate of epoxy groups. In the case of cyanate groups, the former has practically no effect on their conversion whereas the latter decelerates strongly this process. In the present paper the influence of CF on the mechanism of the copolymer formation is considered.     

Temperature dependence of the velocity of ultrasound and electrical conductivity of an epoxy composite with a carbon filler

Experimental data are given on the behavior of the velocity of ultrasound and electrical conductivity as a function of the temperature in an epoxy composite material filled with carbon fiber.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 3, pp. 413–417, September, 1982.