To meet the stringent demands placed on lubricants by the progress of modern technology, it has become necessary to supplement conventional mineral oils and greases. New kinds of lubricants are also needed where products of petroleum crudes cannot even be considered. For example, new and special types of lubricants are required in environments subjected to extreme temperatures, high vacuum, nuclear radiation, and chemically oxidizing or reducing effects. The attention of scientists is therefore being focused on the development of synthetic lubricants for more demanding physical, chemical, and thermal requirements.