Calcium soap lubricants

The article studies the properties of calcium stearate (CaSt2) and lubricants produced on its basis. These lubricants were prepared using sodium stearate and calcium chloride by subsidence from aqueous solutions. The CaSt2 and the light fraction of crude oil were mixed together to obtain lubricating substances. The article shows that CaSt2 had the melting temperature of 142.8 C that is higher than the melting temperature of crude oil (128 C). The compositions of obtained lubricants were studied with optical microscopes. The article shows that the sizes of dispersed particles amount to 1.88 mcm and 0.11 mcm for lubricants having 1 % and 2 % CaSt2 concentration, respectively. As a result of wear trials, it was shown that the friction and wear coefficients of crude oil amounted to 0.099 and 1402 nm, respectively. For the lubricant with 1 % CaSt2 concentration, these coefficients were reduced to 0.0730 and 627.61 nm. Lower wear coefficient (540 nm) was obtained for the lubricant with 2 % CaSt2 concentration. The CaSt2 improved the lubricating property of crude oil but did not improve its oxidative and thermal stability.