Influence of chemically modified ultra-high molecular weight polyethylene on the properties of butadiene nitrile rubber

For the manufacture of frost-resistant oil and petrol-resistant rubber products, one of the most widely used rubbers is nitrile-butadiene rubber (NBR) with a low acrylonitrile content of 17-20 %. However, the technical properties of its vulcanizates do not always meet all high performance requirements. Therefore, the study of the possibility of improving the technical characteristics of vulcanizates based on frost-resistant NBR is an urgent task. This paper presents the results of studying nitrile-butadiene rubber BNKS-18AMN filled with ultra-high molecular weight polyethylene (UHMWPE). A feature of this work is the study of the possibility of increasing the technical properties of the obtained elastomeric composites by increasing the interaction between chemically inert UHMWPE and BNKS-18AMN using the chemical modification of UHMWPE. The modification of UHMWPE was carried out by chemical etching in a solution of chromic acid for 3 and 20 hours. A complex of laboratory studies of the obtained samples was carried out. The influence of the duration of chemical etching of UHMWPE on the rheological and vulcanization properties has been studied on the analyzer of the processing of rubber. It is shown that the filling of UHMWPE into BNKS-18AMN, in general, leads to an increase in the viscosity of the rubber compound. Chemical etching of UHMWPE leads to a decrease in the rate of vulcanization and the density of the three-dimensional spatial structure of the vulcanizate. The study of the physical and mechanical properties in tension, wear resistance during abrasion and swelling in standard hydrocarbon liquid for testing rubbers SZR-3 showed that chemical etching of UHMWPE leads to a decrease in strength characteristics, but at the same time leads to an increase in resistance to abrasion and has no significant effect on swelling. The study of changes in the properties of samples after heat exposure showed that chemical etching of UHMWPE significantly reduces the resistance to thermal oxidative destruction in the presence of atmospheric oxygen, but does not affect the resistance to thermal aging in the SZR-3 hydrocarbon environment.