Complex Of Physicomechanical Properties Research Articles

The Study of the Effect of Thermal Deformation Treatment Modes on the Microstructure and Properties of the Heat-Resistant Nickel Alloy VZH159

The development and introduction of new nickel-based heat-resistant alloys with a special combination of an increased complex of physicomechanical properties is a priority task for modern materials science.

Influence of the Size of Nanoparticles and Their Agglomerates on the Physicomechanical Properties of Epoxynanocomposites

In this work, the relations between the parameters of the structure of epoxy nanodisperions and nanocomposites and a complex of physicomechanical properties of epoxynanocomposites upon the distribution of nanoparticles on nano- and microlevels are established. It is shown that the morphology of epoxy nanocomposites and the size of agglomerates in an epoxy oligomer are almost unchanged during hardening upon the transition of a binder from liquid to solid state (matrix) both on the nanolevel (to ~100 nm) and on the microlevel (to ~390 nm). It is found for the first time that the optimal physicochemical properties are achieved for nanodispersions and nanocomposites only upon the formation of agglomerates of nanoparticles 150–200 nm in size in the structure of epoxynanocomposites.

MODIFICATION OF EPOXY POLYMERS WITH THE USE OF NANOSIZED OF ALUMINIUM OXIDE

The aim of this work was to improve the physical, chemical and mechanical properties of epoxy composites with the use of nanosized aluminium oxide. The studies proved the possibility of directional control of the operational properties of epoxy composites by the use of small additions of nanosized aluminium oxide ensuring the creation of epoxy composites with high performance, satisfying the requirements of most industries. The rational content of aluminium oxide as a nanostructuring additive in an epoxy composition was selected (0,05 parts by weight). It ensures an increase in the complex of physico-mechanical properties (the breaking stress increases 3.3-fold, and the flexural modulus increases by 27%, the breaking stress in compression improves by 43%, the breaking stress and the tensile modulus of elasticity increases by 47-50%, the toughness increases 3-fold, and the hardness increases by 67%), while maintaining heat resistance. The introduction of nanosized aluminium oxide changes the parameters of the epoxy oligomer curing kinetics: the gelation duration increases from 45 to 75 minutes, and the duration of cure, from 53 to 100 minutes, while the maximum curing temperature is practically unchanged. Thus, the developed materials may be used for sealing electronic articles, for impregnating and filling components in aircraft engineering, shipbuilding and, automotive industry.

Influence of the nature of the solvent on the processes of structuring in solutions of cellulose acetates

It is shown that the presence in the macromolecular chain of a polymer of different functional groups makes it possible to obtain controllable polymer-polymer and polymer-solvent contacts and so get systems with a set complex of physicomechanical properties. It has been established that use of a solvent preferentially interacting with the hydroxyl groups of cellulose acetate gives systems differing in all the parameters studied from those in which as second component a solvent is used solvating the acetate groups. With worsening of the quality of the solvent the processes of structuring are extended in time and are accompanied by formation of structures with a different level of orientation.

The mechanical properties of polyethylene terephthalate glass after deformation in adsorbing media

The mechanical behaviour of amorphous PETP has been investigated after deformation in n-propanol. Such deformation has resulted in the formation of specific micro-fissures and the fissured PETP has a new complex of physico-mechanical properties when tested. The stretching tests lead to the assumption that the micro-fissurer formation causes a polymer transition to a new structural state.