Mechanical and Tribological Properties of Polytetrafluoroethylene Composites with Carbon Fiber and Layered Silicate Fillers.

Mixtures of layered silicates (vermiculite and kaolinite) and carbon fibers were investigated as filler materials for polytetrafluoroethylene. The supramolecular structure and the tribological and mechanical properties of the resulting polymer composite materials were evaluated. The yield strength and compressive strength of the polymer increased by 55% and 60%, respectively, when a mixed filler was used, which was attributed to supramolecular reinforcement of the composites. In addition, the wear resistance increased by 850 times when using vermiculite/kaolinite fillers, which was due to protection of the surface by the formation of hard tribofilms.

Mechanical and Tribological Properties of Polytetrafluoroethylene Modified with Combined Fillers: Carbon Fibers, Zirconium Dioxide, Silicon Dioxide and Boron Nitride.

The introduction of combined fillers can effectively improve the mechanical and tribological properties of polytetrafluoroethylene (PTFE). In this work, three different types of nanosized fillers (zirconium dioxide, silicon dioxide, and boron nitride) were introduced in a carbon fiber-reinforced polymer matrix for the development of polymer composite materials (PCM). Tensile and compressive testing were carried out, and the hardness of created PCM was evaluated. It is shown that the compressive strength of PCM increased by 30-70%, and the hardness, increased by 38-55% compared to the initial PTFE. The tribological properties of the developed PCM were evaluated under dry friction conditions. An analysis of the results of an experimental study of wear confirmed that the inclusion of combined fillers (two- and three-component) in PTFE significantly increased wear resistance compared to the polymer matrix with a slight increase in the coefficient of friction. It has been shown that the introduction of three-component fillers has an antagonistic effect on the wear resistance of PCMs compared to two-component fillers. The thermodynamic properties of the composites were analyzed by differential scanning calorimetry and a thermomechanical analyzer. The surface morphology of polymer composites after wear testing was studied by IR spectroscopy and scanning electron microscopy to investigate and suggest a possible mechanism for increasing the wear resistance of the developed composites.

Two-Layer Rubber-Based Composite Material and UHMWPE with High Wear Resistance.

The aim of the study is the development of two-layer materials based on ultra-high-molecular-weight polyethylene (UHMWPE) and isoprene rubber (IR) depending on the vulcanization accelerators (2-mercaptobenzothiazole (MBT), diphenylguanidine (DPG), and tetramethylthiuram disulfide (TMTD)). The article presents the study of the influence of these accelerators on the properties and structure of UHMWPE. It is shown that the use of accelerators to modify UHMWPE leads to an increase in tensile strength of 28-53%, a relative elongation at fracture of 7-23%, and wear resistance of three times compared to the original UHMWPE. It has been determined that the introduction of selected vulcanization accelerators into UHMWPE leads to an increase in adhesion between the polymer and rubber. The study of the interfacial boundary of a two-layer material with scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) showed that the structure is characterized by the presence of UHMWPE fibrils localized in the rubber material due to mechanical adhesion.

Effect of Borpolymer on Mechanical and Structural Parameters of Ultra-High Molecular Weight Polyethylene.

The paper presents the results of studying the effect of borpolymer (BP) on the mechanical properties, structure, and thermodynamic parameters of ultra-high molecular weight polyethylene (UHMWPE). Changes in the mechanical characteristics of polymer composites material (PCM) are confirmed and complemented by structural studies. X-ray crystallography (XRC), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and infrared spectroscopy (IR) were used to study the melting point, morphology and composition of the filler, which corresponds to the composition and data of the certificate of the synthesized BP. Tensile and compressive mechanical tests were carried out in accordance with generally accepted standards (ASTM). It is shown that BP is an effective modifier for UHMWPE, contributing to a significant increase in the deformation and strength characteristics of the composite: tensile strength of PCM by 56%, elongation at break by 28% and compressive strength at 10% strain by 65% compared to the initial UHMWPE, due to intensive changes in the supramolecular structure of the matrix. Structural studies revealed that BP does not chemically interact with UHMWPE, but due to its high adhesion to the polymer, it acts as a reinforcing filler. SEM was used to establish the formation of a spherulite supramolecular structure of polymer composites.