Composition and technology effect on the structure and properties of frost-resistant elastomeric materials based on blends of polar and nonpolar rubbers

Abstract

Elastomeric materials for sealing devices operated in the Far North, including the Republic of Sakha (Yakutia), must be resistant to working environments and have frost and wear resistance with acceptable physical and mechanical properties. Some of the listed properties are mutually exclusive and are not always achievable in materials based on individual rubber. Thus, one promising method for sealing elastomeric materials is the use of rubber mixtures. In this study, model blends based on nitrile-butadiene (BNKS-18), butadiene (SKD), and isoprene (SKI-3) rubbers were studied. Nitrile butadiene rubber was chosen as the component of the mixture responsible for resistance to working environments, and diene rubbers (SKD and SKI-3) were chosen as the components responsible for frost resistance. The addition of SKI-3 also suppressed the crystallization of SKD butadiene rubber. An increase in the BNKS-18 content enhanced the physical and mechanical properties and resistance to wear and non-polar oils. A decrease in lowtemperature properties and resistance to polar oils was also observed. Additionally, studies of the structure of the obtained materials by atomic force microscopy were carried out, which proved the uniformity of the distribution of particles of the dispersed phase, the size of which did not exceed 1-5 μm. The optimal ratio of butadiene-nitrile to diene rubbers was 70:30 phr. At this ratio, the obtained elastomeric materials meet the requirements of sealing materials for operation in cold climates.