D.I. Chukov

Surface treatment of carbon fibers-fillers for polymer matrixes

The processes of chemical and thermal oxidization modifying the surface of UKN-5000 and VMN-4 carbon fibers are studied to provide their adhesion to a polymer matrix during formation of a composite material. Impact of the surface treatment parameters on structure and mechanical properties of the carbon fibers is studied. It is shown that the surface modification of the fibers is an efficient way to strengthen adhesion of the fibers to a polymer matrix, which provides valuable realization of mechanical properties of the fibers during their work in the content of a composite.

Strength and thermophysical properties of composite polymer materials filled with discrete carbon fiber

The structure and properties of carbon-filled composite materials for tribological applications based on ultrahigh molecular weight polyethylene that are obtained by deformation-induced solid-phase synthesis are investigated. It is shown that the addition of graphite and carbon fiber to a polymer material allows one to improve its tribological and thermophysical properties. An increase in the physical and mechanical characteristics is observed only upon the addition of carbon fiber, while the inclusion of graphite in a matrix polymer gives rise to embrittlement of the material.

Quasicrystalline Powders as the Fillers for Polymer-Based Composites: Production, Introduction to Polymer Matrix, Properties

Powders of icosahedral Al65Cu23Fe12 and decagonal Al73Cu11Cr16 quasicrystalline intermetallics were synthesized by the mechanical alloying in combination with subsequent annealing. The conditions of mechanical alloying were purposely chosen to obtain the composite materials filled by dispersed (<3 μm) quasicrystalline particles. A number of silanes were tested for the surface treatment of quasicrystalline particles in order to provide the uniform distribution of quasicrystals over the polymer melt and chemical binding with the polymer matrix and the most efficient silane type was found. The composites based on ethylene-vinyl acetate EVA, polysulphone PSU, and polyphenylene sulfide PPS were produced by the filling with quasicrystalline powders. The study of rheological characteristics has shown that high fluidity of the melt is retained, while uniform distribution of quasicrystalline particles over the polymer is provided. The data of mechanical and physical properties are reported.

Structure and properties of composites based on polyphenylene sulfide reinforced with Al-Cu-Fe quasicrystalline particles

Structural, mechanical, and thermal properties of polyphenylene sulfide (PPS) filled with Al-Cu-Fe quasicrystals particles were studied. It was shown that the introducing of quasicrystalline fillers into the polymer matrix results in the increase in Young’s modulus, hardness, and toughness of the polymer. Quasicrystalline fillers can improve thermal properties of PPS, including heat resistance index, Vicat softening temperature, thermal diffusivity, and thermal conductivity.

Structure and mechanical properties of self-reinforced ultra-high molecular weight polyethylene:

Ultra-high molecular weight polyethylene-based self-reinforced composite materials were studied. Surface of the ultra-high molecular weight polyethylene fibers was modified by direct fluorination and nitric acid treatment. Structure and mechanical properties of self-reinforced ultra-high molecular weight polyethylene depending on the content and type of modified fibers were studied. It was shown that self-reinforcing of ultra-high molecular weight polyethylene allows to obtain materials with improved strength–elastic properties. Tensile strength and Young’s modulus of the self-reinforced composite materials are more than three times higher than that of the unfilled ultra-high molecular weight polyethylene.

Thermal properties of carbonized composite materials based on carbon filled elastomeric matrices

Abstract The paper presents the results of thermal studies of carbonized composites based on carbon filled nitrile-butadiene rubber. It was shown that carbon fibers (CF) increase the thermal conductivity of the composites and reduce their linear expansion, whereas carbon nanotubes (CNTs) practically do not change the linear expansion of the composites; instead, they effectively increase their thermal conductivity. The thermal conductivity of the composites with 25 PHR of CNTs exceeds the thermal conductivity of the composites reinforced with 25 and 50 PHR of CF. Thus, CNTs more effectively increase thermal conductivity than CF due to the appearance of additional heat transfer bridges. It was found that the composites have very high values of the storage modulus at room temperature (16–20 GPa), and it is about 4–5 GPa at 300°C, which is almost impossible for traditional polymer matrix composites.

Bulk Oriented UHMWPE/FMWCNT Films for Tribological Applications

Bulk oriented films based on ultrahigh molecular weight polyethylene (UHMWPE) with a drawing ratio of 35 were prepared by using a low solvent concentration. Bulk oriented films were filled with fluorinated multi-walled carbon nanotubes (FMWCNTs). The structure of bulk oriented films on UHMWPE, which were manufactured at different stages of orientation, was investigated by scanning electron microscope (SEM) and differential scanning calorimetry (DSC). The addition of FMWCNTs at a concentration of 0.05 wt % in bulk oriented UHMWPE films led to an increase in the tensile strength by 10% (up to 1020 ± 23 MPa) compared to unfilled oriented films. However, the addition of FMWCNTs at a concentration of more than 0.5 wt % led to a decrease in tensile strength due to excessive accumulation of nanotubes and hindering of self-diffusion of UHMWPE macromolecules. The multiple increase in tensile strength, doubling the hardness, the formation of fibrillar structure, and the presence of carbon nanotubes led to a significant increase in tribological properties in bulk oriented films. Bulk oriented UHMWPE/1% FMWCNT films can be operated at a maximum contact pressure that is 18 times higher and exhibit a specific wear rate more than an order of magnitude and less than the traditional UHMWPE of isotropic structure. Bulk oriented UHMWPE/1% FMWCNT films have an extremely low dry coefficient of friction (COF) of 0.075 at a contact pressure of 31 MPa. The developed bulk oriented films can be used for manufacturing frictional surfaces for sliding bearings, or for acetabular cups for knee and hip endoprostheses.