Polymer Nanocomposites Exploited Under The Arctic Conditions

Several technologies of the preparation of nanocomposites based on ultra-high-molecular-weight polyethylene were developed. The first technology is based on mechanical activation of layered silicates with surfactant before addition into polymer matrix. The second technology represents mixing of ultra-high-molecular-weight polyethylene with nanoparticles by joint mechanical activation in a planetary mill. The third technology is based on mixing of ultra-high-molecular-weight polyethylene with nanoparticles in liquid media under continuous ultrasonic treatment. Common features of these technologies are reaching of filler uniform distribution in a polymer matrix and significant improvement in the mechanical properties. Also, supramolecular structure of the composites was studied

Influence of Carbon Fibers on Structure and Properties of Polytetrafluoroethylene

In this paper, we studied the effect of carbon fibers on the performance properties of polymer composites based on polytetrafluoroethylene. It was shown that the introduction of PTFE carbon fibers significantly improved tribological and mechanical properties of the composite. The correlation between the performance properties and supramolecular structure was found. Initial lamellar structure of the polymer became less in size without significant changes in morphology when filled. Such process was accompanied by the increase of crystalline regions number and the crystallinity degree of composite. Structural studies have shown that materials with more densely packed and highly crystalline structure have increased mechanical and tribological properties. The developed materials can be used in friction units of machines and devices, where the use of lubricants is not acceptable or restricted

Production of Synthetic Wollastonite Using Gypsum Technogenic Raw Materials

The paper analyzes the literature in the field of synthetic wollastonite production using gypsum technogenic raw materials. Using the example of the complex processing of boric acid production wastes the possibility of obtaining synthetic wollastonite at different modes of waste processing is shown. Possible areas of the practical application of the obtained wollastonite are analyzed. Keywords: gypsum technogenic raw materials, borogypsum, wollastonite, technogenic waste, concrete fillers, polymeric composite materials

Tribological properties of ptfe filled with carbon fibers and solid lubricant

In this paper, the effect of carbon fibers with tungsten disulfide and ultrafine PTFE on the properties and structure of PTFE are investigated. The results showed that PTFE filled with carbon fibers/solid lubricant particles has increased wear resistance and a low coefficient of friction. It is shown that high wear resistance obtained for PTFE filled with carbon fibers/tungsten disulfide compared to that filled with carbon fibers/ultrafine PTFE. It is found that the PTFE filled with complex fillers has high operational performance, which cannot be achieved using a single filler. The results of experimental studies of the structure of PTFE and composites by X–ray analysis and SEM are presented