Enhancement of wear resistance of epoxy composites by introduction of microencapsulated lubricants and magnesium oxide particles

Wear of polymer materials in friction units of transport equipment affects the service life and reliability of rolling stock. The aim of this study was to improve the wear resistance of epoxy composites based on ED-20 resin by introducing magnesium oxide (MgO) particles and polyester microcapsules containing a lubricant. Microcapsules with a size of 5–30 μm were synthesized by interfacial polycondensation of sebacoyl chloride with polyhydric alcohols. Physicomechanical properties were determined by indentation using a NanoTest 600 instrument, while tribological characteristics were measured using an II-5018 friction testing machine in a shaft–pin configuration at a load of 55 N and a sliding distance of 2200 m. The optimal composition was identified as ED-20 + 1 wt.% MgO + 1 wt.% A237 microcapsules containing I-40 oil. This composition provided an 81,5% reduction in the mass wear rate and a decrease in the coefficient of friction from 0,40 to 0,23. Based on ATR-FTIR and SEM-EDS data, a three-stage model of the formation and cyclic renewal of a composite tribolayer was proposed. The results may be used in the development of self-lubricating materials for friction units of rail transport.

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