Ricerc@Sapienza

Over the past years, there has been an increasing interest in natural ester insulating liquids for application in power transformers, thanks to their higher environmental compatibility and lower fire point, as compared to conventional mineral oils. The main function of a transformer oil is its ability to dissipate heat, while ensuring electrical insulation. Among the various influencing parameters, it is well known that heat exchange in a liquid is also affected by its viscosity.

Since ancient times, lubricants have been applied in different fields of technology and, from the very beginning, there has been a wide interest on improving some of their physical-chemical properties. The turning point in the development of lubricants came in the twentieth century, when modern synthetic ester base fluids were realized. In fact, with respect to “natural” lubricants (fats and mineral oils), they can be modified in order to optimize some specific technological properties; in particular, it is desirable that they present high viscosity index and a low pour point.