Mesomorphism and Tribotechnical Characteristics of Lubricant Compositions with Mesogenic Additives Carboxylates Cu(II)

The purpose of the work is to characterize the lubricants based on Llitol-24 and synthetic solidol with additives copper(II) carboxylates when using them in friction nodes in loading conditions and temperature. The lubricant compositions with additives copper(II) carboxylates based on synthetic solidol and Litol-24 form the columnar mesophases depending on thermodynamical conditions and concentration of additives.

Methods. We study the lubricant compositions with dielectric spectroscopy and и polarization light microscopy. The studies lubricant compositions are tested on the frictional machines by preceding authors, which performed their synthesis and numerical estimations for their geometry parameters. It is shown, that the columnar mesophase formed by the compositions with copper(II) carboxylates simulates favourable tribological conditions for lubrication (reduction of the friction coefficient at the appointed range of additive concentrations and reduction of wear) and unlike to crystalline phases, shows orientation effects at the surface of interacting surfaces of machine elements and devices. These factsmotivate the study of influence of physicochemical properties and composition on mesomorphism of considered lubricant compositions.

Results. In our measurements, we found the main dielectric characteristics of two kinds of the lubricant compositions: dielectric constant and dielectric loss, electroconductivity, dissipation factor, the Arrhenius functions are plotted, and the activation energies of the lubricant compositions we study are calculated. The microphotogram for textures of the lubricant compositions depending on temperature and concentrations are received. The differences in mesomorphic properties of the lubricant compositions with additives Cu(II) valerate and isovalerate are confirmed.

The conclusion of the work is that the composition of the lubricant is optimized by the choice of additive concentration, the length of the mesogenic chain of the copper(II) carboxylate molecule and its conformation.

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