The thermal behaviour of cuts of 2-ethyl hexyl oleate, octyl oleate, 2-ethyl hexyl oleyl oxide and octyl oleyl oxide were determined by TGA-DTA analysis, after characterisation of the products to determine purity. Most of the acyl chains of those fatty esters and fatty ethers were oleic chain and the products were fluid. The thermal stability of each liquid was very good as all decomposed at temperatures between 250 degrees C and 300 degrees C. All evaporated before reaching their decomposition temperature. They are new molecules which could be used as lubricants.