Esters in Synthetic Lubricants


Dr. Hermann Zorn[1] of I.G. Farben Industries in Germany began[when?] to search for lubricants with the properties of natural oils but without the tendencies to gel or gum when used in an engine environment. His work[2][3] led to the preparation of over 3500 esters in the late 1930s and early 1940s including diesters, polyolesters, and banana oil. During the same time period in the United States, Dr. William Albert Zismann[4] working at the U.S. Naval Research Laboratory (NRL) was also synthesizing esters, especially diesters.

The first real synthetic engine oils appeared for aircraft engines in World War II concurrently in Germany and in the United States. The motivation in Germany may be related primarily to resource issues, but also to functional performance requirements. The base oils for aircraft engines in Germany were based on a blend of an adipic acid ester with a poly(ethylene) oil[5], e.g., polymerized olefins/ethylene. Because synthetic oils made engine starting in winter easier and significantly decreased soot deposits in oil radiators, the United States Army Air Forces adopted polyglycols (polypropylene glycol monobutylethers) beginning in March 1944.[6][7]