Synthesis of zinc borate by inverse emulsion technique for lubrication |
| |
Authors: | Sevdiye Atakul Savrık Devrim Balköse Semra Ülkü |
| |
Institution: | 1.Department of Chemical Engineering,Izmir Institute of Technology,Urla,Turkey;2.Akzo Nobel Powder Coatings,Izmir,Turkey |
| |
Abstract: | Lubricating oil additives based on boron compounds are promising materials for lubrication due to their tribological advantages
such as antiwear efficiency, good film strength, and high temperature resistance. This article deals with the preparation
of zinc borate particles that are well dispersed and colloidally stabilized in mineral oil. This method starts with preparing
two inverse emulsions (water-in-oil) with sorbitan monostearate (Span 60) as a surfactant, light neutral oil as a continuous
phase, and the aqueous solutions of borax decahydrate (Na2B4O7·10H2O) and zinc nitrate (Zn(NO3)2·6H2O) as the dispersed phases. The produced particles were zinc borate crystals having both rod-like and spherical morphologies,
and the diameters of spherical particles were changing between 20 and 30 nm. FTIR spectra of the obtained particles showed
the characteristic peaks of trihedral borate (B(3)-O) and tetrahedral borate (B(4)-O) groups as well as the specific peaks
of the sorbitan monostearate. TG showed 30.42% and 22.08% mass loss at 600 °C for the samples prepared by inverse emulsion
and precipitation techniques, respectively. The endothermic peak at 50 °C is observed due to the melting of sorbitan monostearate
and the heat of melting is evaluated as −3.50 J/g. Tribological studies revealed that sorbitan monostearate not only outperformed
as a dispersing agent of inorganic particles, but also it proved to be an anti-wear agent. Zinc borate produced by precipitation
decreased the wear scar diameter from 1.402 to 0.639 mm and the friction coefficient from 0.099 to 0.064. The inverse emulsion
was effective in decreasing wear scar diameter and the friction coefficient by lowering them to 0.596 and 0.089 mm, respectively. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|