Thermogravimetric evaluation of the effect of LiBF4 on the thermal stability of three engine lubricants

Publication date: Available online 14 October 2019Source: Journal of Molecular LiquidsAuthor(s): Pei-Hsuan Tung, Bin Laiwang, Chi-Min Shu, Kuang-Hua HsuehAbstractModern refined lubricants have several advantages over their predecessors. However, numerous modern lubricants are environmentally unfriendly, and professional technicians must dispose of lubricant by-products at recycling plants. The primary problem of lubricant by-products is their susceptibility to accidental fire. Both environmental pollution and lubricant-related fire hazards affect the lives of people who live and work near lubricant recycling plants. To examine additives that might alleviate fire hazards, this study tested three types of synthetic engine lubricants with an additional lithium-based salt—LiBF4. The values of mass loss and differential mass loss were obtained through thermogravimetry. The differential isoconversional (Friedman method), Flynn–Wall–Ozawa, and ASTM E698 methods were applied to calculate the apparent activation energy (Ea). Results revealed that LiBF4 could improve the efficiency of engine lubricants. Additional tests were conducted using periodic temperature fluctuation and isothermal simulation models to predict changes during real-world use. Fourier transform infrared spectroscopy showed that LiBF4 could suppress the generation of carbonyl groups (CO) after being mixed with a lubricant.
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research