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What it Takes to be a Commercial Aviation Jet Engine Lubricant
Debbie Sniderman
FEB 28, 2020
Below is just an excerpt...
Quote
Chemistries: Esters
Performance from today's jet engine lubricants must go well beyond the capability of petroleum-based oils. That's why most of them are based on synthetic polyolesters, which provide the needed thermal stability. Esters are synthetic fluids formed by reacting fatty acids and alcohols, producing water as a byproduct, which is driven off with heat. One of the primary raw materials that serves as the source of fatty acids is palm kernel oil or coconut oil.
Esters are polar molecules and very hygroscopic, having a natural affinity for water and readily absorbing it from the atmosphere. So, it is critical to keep ester-based lubricants away from water. Water contamination of ester fluids can cause hydrolysis, which may form acids, especially in sealed systems. This is a battle the aviation lubrication industry fights continuously.
To keep lubricants safe from this threat, they are packaged in metal, which should always be kept sealed until use. Opened containers should be used quickly to protect it from absorbing water from the atmosphere.
There are two basic types of esters in use today: diesters and polyolesters. Diesters are relatively simple molecules compared to the more complex polyester molecules. Diesters have slightly lower viscosities than polyolesters, and both have good fluidity at cold temperatures compared to other lubricants. This is important because they must routinely work in temperatures of −50° C when aircraft are flying...
What it Takes to be a Commercial Aviation Jet Engine Lubricant
Debbie Sniderman
FEB 28, 2020
Below is just an excerpt...
Quote
Chemistries: Esters
Performance from today's jet engine lubricants must go well beyond the capability of petroleum-based oils. That's why most of them are based on synthetic polyolesters, which provide the needed thermal stability. Esters are synthetic fluids formed by reacting fatty acids and alcohols, producing water as a byproduct, which is driven off with heat. One of the primary raw materials that serves as the source of fatty acids is palm kernel oil or coconut oil.
Esters are polar molecules and very hygroscopic, having a natural affinity for water and readily absorbing it from the atmosphere. So, it is critical to keep ester-based lubricants away from water. Water contamination of ester fluids can cause hydrolysis, which may form acids, especially in sealed systems. This is a battle the aviation lubrication industry fights continuously.
To keep lubricants safe from this threat, they are packaged in metal, which should always be kept sealed until use. Opened containers should be used quickly to protect it from absorbing water from the atmosphere.
There are two basic types of esters in use today: diesters and polyolesters. Diesters are relatively simple molecules compared to the more complex polyester molecules. Diesters have slightly lower viscosities than polyolesters, and both have good fluidity at cold temperatures compared to other lubricants. This is important because they must routinely work in temperatures of −50° C when aircraft are flying...