Study PAO VS Esther

[Feffman]

Hi All:

Has anyone done an independent study of PAO synthetics versus esther based synthetics? I don't want PR stuff from an oil manufacturer. Just a thought!

Feff

 

[Kaboomba]

You may find this informative--I did:

http://www.machinerylubrication.com/article_detail.asp?articleid=2021

Enjoy!

 

[Familyguy]

Nobody compares to Esther. She made the best biscuits of any girlfriend I ever had....

Oh wait...

 

[StevieC]

Originally Posted By: Familyguy
Nobody compares to Esther. She made the best biscuits of any girlfriend I ever had....

Oh wait...

 

[Silber Igel]

Originally Posted By: StevieC
Originally Posted By: Familyguy
Nobody compares to Esther. She made the best biscuits of any girlfriend I ever had....

Oh wait...

Gafaaaawwwwww!!!

 

[BobFout]

Originally Posted By: Familyguy
Nobody compares to Esther. She made the best biscuits of any girlfriend I ever had....

Oh wait...


She have a sister named Pam?

 

[Doug Hillary]

Hi,
I think her surname was Williams...............

 

[labman]

Actually that was her middle name, Poly Esther Williams.

Good description but no numbers. Great point about the difference between base stock and a formulated oil.

 

[BobFout]

Her last name wasn't Pants?

 

[Drew2000]

Wow, you guys are old! When you pull into a filling station do 'ya ask for $2 of Ethyl?

 

[Silber Igel]

Originally Posted By: Drew2000
Wow, you guys are old! When you pull into a filling station do 'ya ask for $2 of Ethyl?

Well noooo! (But I do refer to high octane fuel as "Hi-Test"...

I do miss those nifty "Ethyl" stickers on the gas pumps....

 

[Feffman]

Originally Posted By: Silber Igel
Originally Posted By: Drew2000
Wow, you guys are old! When you pull into a filling station do 'ya ask for $2 of Ethyl?

I do miss those nifty "Ethyl" stickers on the gas pumps....


Not too mention all the jokes about "pumping Ethyl". Kaboomba, thanks for the link.

Feff

 

[stenerson]

According to the article poly ester have poor hydrolytic stability. How would that effect an engine oil?

 

[vxcalais]

Originally Posted By: stenerson
According to the article poly ester have poor hydrolytic stability. How would that effect an engine oil?


Would it mean that if you had a very small coolant leak, or high combustion fluid type bi products, you would be knackered ???

 

[saaber1]

Originally Posted By: stenerson
According to the article poly ester have poor hydrolytic stability. How would that effect an engine oil?


It doesn't:

"Redline's reply is correct. Hydroscopic refers to a liquid's capacity to absorb and solubilize water. Higher molecular weight esters will only solubilize 0.1 to 0.2% water, and even this will be released under vacuum and heat.

Tom NJ"

http://www.bobistheoilguy.com/forums/ubb...780#Post1625780

Also here is a good article on Esters FYI:

http://www.bobistheoilguy.com/forums/ubb...994#Post1252272

 

[Tom NJ]

Saaber1 is correct - it doesn't - but for a different reason.

Hydroscopicity, a liquid's capacity to absorb and solubilize water, is different than hydrolytic stability, a liquid's capacity to react with water.

Esters are not considered very hydrolytically stable, but they vary according to structure, and the conditions needed to break them are pretty severe. The net effect in motor oils is not significant - you may see a rise in TAN but not the corrosive type.

Polyol esters are more hydrolytically stable than diesters, which were used for many years in synthetic motor oils without problems. Advanced POEs are quite hydrolytically stable. Nearly 40 years of ester use in motor oils have not demonstrated any performance issues with respect to their hydrolytically stability.

Tom NJ

 

[labman]

Esters will react with anything with an acid or hydroxyl including water. However, not very fast except at high temperatures. By the time the temperature gets high enough for much to react, most of the problem things will have evaporated off. Glycol from the coolant could be a problem. Who know what strange new esters could form.

Mixing polyol and dibasic acid esters could lead to polyesters forming. I used to use them to make paint resins. So watch frankenmixes and coolant leaks. Otherwise, as stated, they have an excellent record.

 

[Bruce T]

Wow, great discussion. I didn't know that polyol esters could react with diesters or antifreeze. That's something to watch.

 

[Tom NJ]

Originally Posted By: labman
Mixing polyol and dibasic acid esters could lead to polyesters forming. I used to use them to make paint resins.


True, but the POE and diester types used in synthetic lubricants will not generally transesterify except at temperatures beyond car engines. It would be a concern for jet engine lubricants, but no such mixtures are used there. Even if polyesters (we called them complexed esters) are formed, they are also stable, just higher in viscosity. Complexed esters are widely used in synthetic lubricants - great physical properties such as pour point and VI, but not so good for high temperature coking.

Advanced POEs are branched at specific locations on the carboxylic acid moiety, thus stearically hindering water attack at the ester linkage. This also reduces the methylene hydrogens which improves high temperature oxidative stability and coking. Properly structured these are the cream of POEs for high temperature use. Overkill for car engine oils, but the darling of the latest generation jet engine oils and industrial chain lubricants.

Tom NJ

 

[rcy]

Originally Posted By: Tom NJ


True, but the POE and diester types used in synthetic lubricants will not generally transesterify except at temperatures beyond car engines. It would be a concern for jet engine lubricants, but no such mixtures are used there. Even if polyesters (we called them complexed esters) are formed, they are also stable, just higher in viscosity. Complexed esters are widely used in synthetic lubricants - great physical properties such as pour point and VI, but not so good for high temperature coking.

Advanced POEs are branched at specific locations on the carboxylic acid moiety, thus stearically hindering water attack at the ester linkage. This also reduces the methylene hydrogens which improves high temperature oxidative stability and coking. Properly structured these are the cream of POEs for high temperature use. Overkill for car engine oils, but the darling of the latest generation jet engine oils and industrial chain lubricants.

Tom NJ


I understood everything right up until the word 'true', then you lost me.