ABSTRACT
Conventional polyalkylene glycols (PAGs) have very low solubility in hydrocarbon oils. More research has been directed towards understanding the performance properties of OSPs. The oxidation stability of Oil Soluble PAG (OSP) is similar to many conventional PAGs. The surface activity of OSPs in combination with other surface active additives has also been explored. Alcohol initiated OSPs prepared via conventional alkali hydroxide catalysis have a terminal hydroxyl group. OSPs that are biodegradable may be a popular choice for formulating environmentally acceptable lubricants such as those required under the regulations of the Vessel General Permit in the United States and the EU Eco-label. The concept of using OSPs to carry surface active additives to metallic surfaces has also been illustrated with extreme pressure additives. One area of particular interest for capped OSPs is in transportation lubricants such as transmission fluids and engine oils where there continues to be progress in developing lower viscosity lubricants particularly for passenger car motor oils.
