Mendes, José Ubiragi de LimaRodrigues, Luanda Kívia de Oliveira2018-05-162018-05-162018-01-26RODRIGUES, Luanda Kívia de Oliveira. Síntese de caracterização de nanolubrificante de Licuri de gado. 2018. 105f. Tese (Doutorado em Engenharia Mecânica) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2018.https://repositorio.ufrn.br/jspui/handle/123456789/25225Vegetable oils are the alternative for the production of biodegradable and nontoxic lubricants, but the high oxidative rate is a complicating factor. Therefore, this work proposes the use of transesterified Licuri Gado oil, as base oil, since the Licuri oil is saturated and the transesterification delays its degradation, in contrast to reduce its viscosity and thermal dissipation capacity. To increase the thermal dissipation capacity of the fluid and act as an extreme pressure additive it is proposed to add the transesterified oil with Nanoparticles (NP's). The nanoparticles were produced by milling and by Polymeric Precussors. Then they were characterized by MEV, DRX and TG. The oil was extracted by cold pressing and then subjected to two transesterification methods: One route with heating and one route without heating. Specific mass, viscosity, acidity index, conductivity and thermal resistivity, thermogravimetry (TG) and tribological tests were performed in the in-natura oil, transesterified and added with the 0.5% by mass concentration of Zinc Oxide nanoparticles (ZnO). These three oil samples were submitted to the tribological test in the cylinder-plane configuration. The NPs of ZnO presented the best relation, size and geometry and were therefore used as additives, where the dispersion was made in the oil by mechanical agitation. In the TG assay the increase in the thermal stability of the oil after transesterification was verified. After additivation of the NPs, the decrease was the acidity, viscosity profile, and the decrease in temperature in the contact body and against body during the tribological test. This corroborates the initial idea that NP's increase the oil's ability to dissipate thermal energy and contribute to the reduction of friction. However, the wear of the test piece was higher, because the NPs acted as a third body, accelerating the wear process. However, the initial hypothesis of the use of ZnO-added Cattle Licurized oil as a biolubricant is not ruled out. However, it is necessary to evaluate their use in applications whose low viscosity is required and the main purpose of the fluid is the dissipation of thermal energy, such as cutting fluid.Acesso AbertoLicuri de gadoNanolubrificanteNanopartículasÓxido de ZincoBiodegradáveldoctoralThesisCNPQ::ENGENHARIAS::ENGENHARIA MECANICA