Keyword: «ultra-high molecular weight polyethylene»

This paper presents the results of comparative studies of the physical and mechanical properties of ultra-high molecular weight polyethylene and modified polymer composite materials (PCM) before and after bench full-scale tests at the climatic test site in Yakutsk. It is established that in the conditions of the sharply continental climate of Yakutia, ultra-high molecular weight polyethylene and a composite containing 5 wt. % of carbon fibers of the brand "Belum" are aging by the fourth month of exposure. In this regard, ultra-high molecular weight polyethylene was modified not only with carbon fibers to increase the physico-mechanical and tribotechnical parameters, but also a stabilizer of the SO-4 brand produced by NIOH SB RAS was introduced. Based on the conducted studies, it was found that the additional modification of the UHMWPE-UV composite with a stabilizer of the CO-4 brand leads to a slowdown in the photo-oxidative processes of the composite in the open air, which has a positive effect on the preservation of physical and mechanical parameters for a long time under the influence of adverse climatic factors. This fact allows us to predict the high performance of products made of the developed material in the conditions of the sharply continental climate of Yakutia.

This paper presents the results of a study of the effect of functional fillers on the properties and structure of ultra-high molecular weight polyethylene (UHMWPE). 2-Mercaptobenzthiazole (MBT), diphenylguanidine (DPG), tetramethylthiuram disulfide (TMTD) and sulfenamide (CBS) were used as functional additives. The concentration of fillers in UHMWPE was 0.5, 1 and 2 wt.%. It has been established that the introduction of functional additives significantly increases the tensile strength characteristics of the initial polymer. Thus, the maximum increase in tensile strength is observed with the introduction of TMTD and DPG, which showed an increase of 44% and 41% compared to the original UHMWPE, respectively. Relatively high wear resistance is observed in composites containing MBT and CBS. The effectiveness of the use of functional additives as UHMWPE modifiers is shown.

The influence of the mixing regime on the properties of low temperature oil-resistant rubbers based on the blend of BNKS-18AMN butadiene-nitrile rubber and GUR 4113 ultra-high molecular weight polyethylene was studied. Different ways of introducing of UHMWPE into the rubber mixture are considered: by mixing before and after the introduction of the main ingredients of the rubber mixture at temperatures up to 80°C (below the melting point of UHMWPE), as well as by preliminary high-temperature (160°C) mixing of rubber and UHMWPE. It was found that preliminary high-temperature mixing of rubber with UHMWPE leads to a decrease in the viscosity of the rubber mixture, as well as a reduction in the scorch time and the achievement of the optimum vulcanization, but does not lead to significant changes in the physical and mechanical properties and oil resistance of vulcanizates.

Accelerated climatic tests of extruded composites based on UHMWPE have been carried out. It has been established that stearic acid, used as a plasticizer, is washed out when exposed to climatic factors. At the same time, a significant degradation of the physical and mechanical characteristics of materials is observed. It has also been shown that the addition of a CO-4 stabilizer as an antioxidant improves the climatic resistance of materials based on UHMWPE, however, their fluidity and extrudability noticeably worsen.