Mobil ad describing how they invented PAO. Wonder if it was written by legal or marketing.
https://energyfactor.exxonmobil.com/scie...3205cf776b6a7c8
https://energyfactor.exxonmobil.com/scie...3205cf776b6a7c8
The invention of PAO......
- Thread starter DeepFriar
- Start date
- Status
I thought PAO was first synthesized in the 1930s...
I might be wrong but maybe Mobil just found a better way to make a slightly more chemically regular PAO but PAO's themselves were already 'known'.
If I remember correctly most 'modern' PAO is made using Boron Triflouride catalyst. However during WWII, the Germans were making synthetic, low Pour Point base oils from ethylene (an Olefin) using Aluminium Chloride as the polymerisation catalyst. The stuff that came out of the Leuna plant sounds a lot like crude PAO. Given that any and all potentially useful German R&D was hoovered up by the Allies after 1945 for future exploitation, maybe the Mobil 'invention' of PAO using BF3 was more of a refining of an existing tech than a true Eureka moment.
If I remember correctly most 'modern' PAO is made using Boron Triflouride catalyst. However during WWII, the Germans were making synthetic, low Pour Point base oils from ethylene (an Olefin) using Aluminium Chloride as the polymerisation catalyst. The stuff that came out of the Leuna plant sounds a lot like crude PAO. Given that any and all potentially useful German R&D was hoovered up by the Allies after 1945 for future exploitation, maybe the Mobil 'invention' of PAO using BF3 was more of a refining of an existing tech than a true Eureka moment.
MolaKule
Staff member
http://www.aukevisser.nl/others/id961.htm
Synthetic oil research and discovery can be found on both sides of the ocean in earnest during the 20's and 30's after the discovery of polymerization and polymerization processes.
Synthetic oil research and discovery can be found on both sides of the ocean in earnest during the 20's and 30's after the discovery of polymerization and polymerization processes.
MolaKule
Staff member
Much of the early work was done on finding more efficient catalyzation processes and lowering cost.
In fact, there is still much research going on to find more efficient catalyzation processes.
In fact, there is still much research going on to find more efficient catalyzation processes.
I have also heard that the original Mobil PAO had problems with seal leakage when it came out. Someone figured it needed polar esters to condition the seals. Without that PAO would have been a bust.
Originally Posted By: DWC28
I have also heard that the original Mobil PAO had problems with seal leakage when it came out. Someone figured it needed polar esters to condition the seals. Without that PAO would have been a bust.
There are certainly drawbacks to PAO. The seal compatibility, price, and additive solubility being the most well known probably.
I have also heard that the original Mobil PAO had problems with seal leakage when it came out. Someone figured it needed polar esters to condition the seals. Without that PAO would have been a bust.
There are certainly drawbacks to PAO. The seal compatibility, price, and additive solubility being the most well known probably.
Originally Posted By: Shannow
Back in the day there was big controversy in that M1 was reputed to have regular dino as a part of it's make-up...additive "carrier oil" was the explaination...PAO didn't play with the additives of the day.
It still doesn't today. Just about all additives use mineral oil as the carrier fluid. You'd be hard pressed to find any additized synthetic product that doesn't have at least a percentage or two of mineral oil. Additive companies typically don't want to increase their prices by using esters when mineral oil does the job just fine at 1/3 to 1/4 the price.
Back in the day there was big controversy in that M1 was reputed to have regular dino as a part of it's make-up...additive "carrier oil" was the explaination...PAO didn't play with the additives of the day.
It still doesn't today. Just about all additives use mineral oil as the carrier fluid. You'd be hard pressed to find any additized synthetic product that doesn't have at least a percentage or two of mineral oil. Additive companies typically don't want to increase their prices by using esters when mineral oil does the job just fine at 1/3 to 1/4 the price.
Synthetic lubricants have been around at least since the 1930s, but received a great boost during WWII when the Germans needed oils with better low temperature flow properties for the Russian front, and were concerned about the availability of conventional oils. German chemists synthesized and evaluated hundreds if not thousands of compounds including synthetic hydrocarbons and numerous esters. These records were scrutinized by the allies after the war and a diester (Di 2-Ethylhexyl Sebacate) was selected by Esso (now ExxonMobil) for use in the early developing jet engines. This first oil was called EEL Oil 1 after Esso Engineering Laboratory and was the basis for the military specification MIL-L-7808. In 1963 POEs (Polyol Esters) were introduced for jet engines offering better high temperature capabilities, and continue to be used today as the exclusive base oil in all commercial and military jets worldwide.
In 1972 the first fully approved synthetic motor oil was developed by Hatco Corporation and marketed by Amsoil. This was also based entirely on diesters, as were most early synthetic motor oils, and performed very well. But market penetration was difficult because the marketers were small underfunded companies and the products were shunned by car manufacturers and major oil. That is until Mobil introduced Mobil 1 shortly thereafter. Their first version was based on a mixture of PAOs and POEs, but the initial grade of 5W-20 was unpopular in a world of 10W-40s and caused leaks in some engines. Mobil increased the viscosity in 1980 to 5W-30 with the introduction of the SF specification, and switched from a POE to a diester correction fluid. Some additives were dissolved in mineral oil, but synthetics were defined by the base oil composition, not the additives.
Tom NJ/VA
In 1972 the first fully approved synthetic motor oil was developed by Hatco Corporation and marketed by Amsoil. This was also based entirely on diesters, as were most early synthetic motor oils, and performed very well. But market penetration was difficult because the marketers were small underfunded companies and the products were shunned by car manufacturers and major oil. That is until Mobil introduced Mobil 1 shortly thereafter. Their first version was based on a mixture of PAOs and POEs, but the initial grade of 5W-20 was unpopular in a world of 10W-40s and caused leaks in some engines. Mobil increased the viscosity in 1980 to 5W-30 with the introduction of the SF specification, and switched from a POE to a diester correction fluid. Some additives were dissolved in mineral oil, but synthetics were defined by the base oil composition, not the additives.
Tom NJ/VA
Pacified!
But why M1 went from POE to Diesters at that time? Cost? Compatibility? Viscosity augmented gave birth to use a lesser ester?
But why M1 went from POE to Diesters at that time? Cost? Compatibility? Viscosity augmented gave birth to use a lesser ester?
Last edited:
Originally Posted By: Ohle_Manezzini
Pacified!
But why M1 went from POE to Diesters at that time? Cost? Compatibility? Viscosity augmented gave birth to use a lesser ester?
From Tom NJ's post it would seem that the POE base oils weren't compensating for the PAO's tendency to shrink seals, so they used diester instead which has higher seal swell tendency.
Pacified!
But why M1 went from POE to Diesters at that time? Cost? Compatibility? Viscosity augmented gave birth to use a lesser ester?
From Tom NJ's post it would seem that the POE base oils weren't compensating for the PAO's tendency to shrink seals, so they used diester instead which has higher seal swell tendency.
Originally Posted By: Ohle_Manezzini
Pacified!
But why M1 went from POE to Diesters at that time? Cost? Compatibility? Viscosity augmented gave birth to use a lesser ester?
To the best of my knowledge, the change from a POE (TMP C8C10) to a diester (Ditridecyl Adipate) was driven by cost. The POE had a higher degree of polarity than the diester based on the Nonpolarity Index (58 vs 82) so less should have been needed for seal compatibility. In addition, the POE had a lower Noack volatility (3 vs 7%), a higher VI (140 vs 135), higher lubricity, and better oxidative stability, all favoring the POE from a technology stand point. At the time, however, POEs were considerably more expensive than diesters. Other factors may have played a role, but I suspect cost was the driver.
Tom NJ/VA
Pacified!
But why M1 went from POE to Diesters at that time? Cost? Compatibility? Viscosity augmented gave birth to use a lesser ester?
To the best of my knowledge, the change from a POE (TMP C8C10) to a diester (Ditridecyl Adipate) was driven by cost. The POE had a higher degree of polarity than the diester based on the Nonpolarity Index (58 vs 82) so less should have been needed for seal compatibility. In addition, the POE had a lower Noack volatility (3 vs 7%), a higher VI (140 vs 135), higher lubricity, and better oxidative stability, all favoring the POE from a technology stand point. At the time, however, POEs were considerably more expensive than diesters. Other factors may have played a role, but I suspect cost was the driver.
Tom NJ/VA
MolaKule
Staff member
Quote:
...To the best of my knowledge, the change from a POE (TMP C8C10) to a diester (Ditridecyl Adipate) was driven by cost. ...At the time, however, POEs were considerably more expensive than diesters. Other factors may have played a role, but I suspect cost was the driver...
That is my understanding as well. While POE was superior in many regards, cost was a driving factor for the change.
Here is the CAS info on the diester:
CAS No. 16958-92-2, Chemical Names: Hexanedioic acid, 1,6-ditridecyl ester, Ditridecyl Adipate (DTDA), Adipic acid, ditridecyl ester.
BTW, for a 5.0 to 5.4 cSt ditridecyl ester, the NOACK is 4.5% to 7.4% for you Noack watchers.
...To the best of my knowledge, the change from a POE (TMP C8C10) to a diester (Ditridecyl Adipate) was driven by cost. ...At the time, however, POEs were considerably more expensive than diesters. Other factors may have played a role, but I suspect cost was the driver...
That is my understanding as well. While POE was superior in many regards, cost was a driving factor for the change.
Here is the CAS info on the diester:
CAS No. 16958-92-2, Chemical Names: Hexanedioic acid, 1,6-ditridecyl ester, Ditridecyl Adipate (DTDA), Adipic acid, ditridecyl ester.
BTW, for a 5.0 to 5.4 cSt ditridecyl ester, the NOACK is 4.5% to 7.4% for you Noack watchers.
Last edited:
MolaKule
Staff member
For comparison, a POE of 4.3 cSt has a Noack of 4.6%.
So, Mobil 1 is a fully syn that went from POE, passed throught Diester and now is on Alkylared Naphtalene ...
- Status
Similar threads
