Formulación y procesado de oleogeles para el desarrollo de nuevas grasas lubricantes biodegradables

Résumé

This work deals with the use of renewable raw materials to develop new completely biodgradable lubricating grease formulations. Different vegetable oils have been used as base oil and several polymers and/or biodegradable gelling agents have been tested as thickeners, e.g. sorbitan and glyceryl monoestearates and the two most abundant biopolymers, cellulose and chitin, or some chemical derivatives. A comprehensive rheological and mechanical characterization of the resulting formulations as well as a thermal analysis, evaluating the influence of the different biodegradable polymers used as thickeners, were carried out. Moreover, a series of tribological tests were performed to evaluate the frictional behaviour of these new greases in simulated conditions of lubrication. As a result of this investigation, a number of formulations, which could potentially be used as biodegradable greases, have been proposed.