About base stocks and additives (not the usual Q!)

[Olas]

Specifically MOS2 interactions with different base stock

Respected members on here have reported using MOS2 in vehicles that spend some time sitting and finding the additive settled out in the bottom of the sump..

With regard to base stock..

I'm not a chemist but my understandings are:
The M part of MOS2 is Molybdenum, a metal.
POE base is polar and 'clings' to metal

Does this mean that MOS2 is less likely to settle out when used in conjunction with Redine, Motul, or any other ester based oil?

My reason for asking is due to my wondering wether I should drop and clean the sump next oil change.

Thanks guys

 

[aquariuscsm]

^^This additive has always had me curious too. I'm not an attitive guy,buy for some reason this one has me wanting to try it. I read nothing but rave reviews about it.

 

[Shannow]

nope, while I understand your question, if it does "cling", it's going to be like attaching a tiny tail to a particle, and it will still fall out.

Make the particles tiny, and they fall out slower, tiny enough, and brownian motion can make them nearly never drop.

But polarity of the additives doesn't do much unless it can dissolve them.

 

[Phishin]

Olas,

I can't envision an ester based oil suspending colloidal MOS2 any better than a typical Group III oil. This chemist can't see how that would be the case.

Yeah, the polar nature of POE has been attributed to clinging to engine parts longer. Maybe. But even if that is the case, that has nothing to do with colloidal MOS2 would suspend better in an ester oil.

I run LM MOS2 in my wife's Subie. What I'm curious about to taking off her Napa Platinum filter this fall. It's gone through two OCI's, each OCI getting a full can of MOS2. I want to see if the filter is clogged up with moly particles.

 

[weasley]

Just because the "Mo" part is a metal element, doesn't mean there is any actual metal in the additive. That's like saying that you have particles of iron metal in your blood, or lumps of calcium metal in milk or sodium metal in your table salt.

The Mo is part of the MoS2 compound. This is, itself, a solid (but not a metal) and is used in additives as a finely-divided powder. Ester base oils, or any other polar molecule, may well be electrostatically attracted to it, which will tend to help in its dispersal in the oil (rather than promote drop-out).

I'm still not a fan of deliberately ADDING ground-up solids to my oil though.

 

[SR5]

Originally Posted By: Phishin
Olas,

I can't envision an ester based oil suspending colloidal MOS2 any better than a typical Group III oil. This chemist can't see how that would be the case.

Yeah, the polar nature of POE has been attributed to clinging to engine parts longer. Maybe. But even if that is the case, that has nothing to do with colloidal MOS2 would suspend better in an ester oil.

I run LM MOS2 in my wife's Subie. What I'm curious about to taking off her Napa Platinum filter this fall. It's gone through two OCI's, each OCI getting a full can of MOS2. I want to see if the filter is clogged up with moly particles.


Let us know what you find, I would be interested.

They say the MoS2 grain size is about 1.5 microns, but I'm not too sure what size your filter goes down to.
You would expect the moly to be everywhere the oil is, so you should find it in the filter, but you would hope it wouldn't actually block the filter. Not sure how you would tell blocked from present by just a visual inspection.

I don't often use moly, but when I do, I've had nothing but good experiences with it. My cars always seem to start easier and run smoother. You can feel the improvement straight away. Not dramatic, but definitely there.

I think a good application would be if you are running a thick oil in a old car to combat leaks, but you lived in a cold area. The MoS2 would bond to the metal surfaces and reduce friction on cold starts.

 

[Olas]

Good information guys, thanks for the explanations.

The analogy of iron in blood helped me understand the counterintuitive (to a non chemist) point that there is no metal in the metal..

Weasley, reading your posts I get the impression you work at McLaren or somewhere similarly esteemed. Go on, fess up, whatcha do day to day?

 

[MolaKule]

To which type of moly are you referring?

There is powdered moly, powdered moly in a colloidal suspension, and soluble moly generally described as MolyDithiocarbamates, or MoDTC or MoDTP.

Originally Posted By: from a previous post by Mola
As explained here regarding friction Modifiers in general:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729029#Post729029


The modern soluble moly additives are primarily Molybdenum Di-Thiocarbamates, or MoDTCs.

There is the Mono-nuclear type, the Di-Nuclear type, and the Tri-Nuclear type. Which one a formulator uses in an oil and how much depends on a number of factors such as application (daily driver, racing) and cost.

In the Tri-Nuclear moly, the core of the MoDTC molecule has more sulfur in order to create or liberate more MoS2 molecules.

This has three advantages, 1) more sulfur for anti-oxidation and hence sludge resistance and 2) more flat plate MoS2 molecules for friction reduction, 3) less MoDTC is needed for friction reduction over the other types of moly.

Think of the MoDTC molecule as a planar object much like a playing card in a deck of plastic coated playing cards.

The flat plate MoDTC molecules tend to stack themselves so that the top cards are sheared off smoothly, thus reducing friction.

(Other friction reducers reduce friction by virtue of allowing their molecular whiskers to be sheared off, much like a mower blade when mowing grass).

In addition, the sharing of ZDDP molecular components with Moly MoDTC helps the ZDDP reduce wear.

So, as a formulator I have a choice as to which type and additive level of MoDTC to use for the application.

 

[ExMachina]

Originally Posted By: SR5
Originally Posted By: Phishin

I run LM MOS2 in my wife's Subie. What I'm curious about to taking off her Napa Platinum filter this fall. It's gone through two OCI's, each OCI getting a full can of MOS2. I want to see if the filter is clogged up with moly particles.

They say the MoS2 grain size is about 1.5 microns, but I'm not too sure what size your filter goes down to.
You would expect the moly to be everywhere the oil is, so you should find it in the filter, but you would hope it wouldn't actually block the filter. Not sure how you would tell blocked from present by just a visual inspection.


I know what you mean, lots of people see old used filter media and all it's really good for is to check for tears/holes, not degree of 'clog-ation' (new word invented by me just now).

If using LiquiMoly MOS2, the popular one, the majority of the moly grains are less than 0.3 micron. http://www.liquimoly.co.uk/assets/pdf/tech/8.pdf ... If most are smaller than 0.3 micron, then the other half is greater than 0.3 micron, and we assume very, very few are greater than say 2 microns in size.
Oil filters are very bad at scouring out anything less than 5 microns in general. Fram Ultra is 80% at all particles greater than about 5 microns, and its about the best oil filter efficiency you'll find; others barely touch
Originally Posted By: SR5
I don't often use moly, but when I do, I've had nothing but good experiences with it. My cars always seem to start easier and run smoother. You can feel the improvement straight away. Not dramatic, but definitely there.

Placebo effect. Gains are nowhere near what anybody can feel.

Originally Posted By: SR5
I think a good application would be if you are running a thick oil in a old car to combat leaks, but you lived in a cold area. The MoS2 would bond to the metal surfaces and reduce friction on cold starts.

I think you're right.

 

[KCJeep]

Originally Posted By: Phishin

I run LM MOS2 in my wife's Subie. What I'm curious about to taking off her Napa Platinum filter this fall. It's gone through two OCI's, each OCI getting a full can of MOS2. I want to see if the filter is clogged up with moly particles.


I have run and cut somewhere between 3-5 filters that had full doses of MoS2. They didn't look one whit different than those without.

 

[KCJeep]

Originally Posted By: Phishin

I can't envision an ester based oil suspending colloidal MOS2 any better than a typical Group III oil. This chemist can't see how that would be the case.


I have long wondered if a diesel HDEO like Rotella would hold MoS2 even better than a typical PCMO, although I have never noticed any problems using MoS2 in PCMO.

 

[DeepFriar]

Originally Posted By: MolaKule
To which type of moly are you referring?


Originally Posted By: from a previous post by Mola
As explained here regarding friction Modifiers in general:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729029#Post729029



In addition, the sharing of ZDDP molecular components with Moly MoDTC helps the ZDDP reduce wear.

So, as a formulator I have a choice as to which type and additive level of MoDTC to use for the application.



One of, one would suppose, a quite long list of choices/materials not revealed by VOA/UOA?

 

[weasley]

Originally Posted By: Olas
Weasley, reading your posts I get the impression you work at McLaren or somewhere similarly esteemed. Go on, fess up, whatcha do day to day?


I wish!! I work for one of the major global motor oil suppliers and have done for 23 years. Most of that time has been spent in product development and technical support, including marine engine oils, truck engine oils, running an analytical laboratory and currently teaching and training on oil technology. I am lucky enough to get involved in some very interesting collaborations and events.

 

[weasley]

Originally Posted By: MolaKule
To which type of moly are you referring?


Originally Posted By: Olas
Specifically MOS2 interactions with different base stock

Assuming Olas was being correctly specific about molybdenum disulphide, rather than using "MOS2" as a proxy for "any old molybdenum additive".

 

[Olas]

Originally Posted By: MolaKule
To which type of moly are you referring?

There is powdered moly, powdered moly in a colloidal suspension, and soluble moly generally described as MolyDithiocarbamates, or MoDTC or MoDTP.

Originally Posted By: from a previous post by Mola
As explained here regarding friction Modifiers in general:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729029#Post729029


The modern soluble moly additives are primarily Molybdenum Di-Thiocarbamates, or MoDTCs.

There is the Mono-nuclear type, the Di-Nuclear type, and the Tri-Nuclear type. Which one a formulator uses in an oil and how much depends on a number of factors such as application (daily driver, racing) and cost.

In the Tri-Nuclear moly, the core of the MoDTC molecule has more sulfur in order to create or liberate more MoS2 molecules.

This has three advantages, 1) more sulfur for anti-oxidation and hence sludge resistance and 2) more flat plate MoS2 molecules for friction reduction, 3) less MoDTC is needed for friction reduction over the other types of moly.

Think of the MoDTC molecule as a planar object much like a playing card in a deck of plastic coated playing cards.

The flat plate MoDTC molecules tend to stack themselves so that the top cards are sheared off smoothly, thus reducing friction.

(Other friction reducers reduce friction by virtue of allowing their molecular whiskers to be sheared off, much like a mower blade when mowing grass).

In addition, the sharing of ZDDP molecular components with Moly MoDTC helps the ZDDP reduce wear.

So, as a formulator I have a choice as to which type and additive level of MoDTC to use for the application.


Mola,

As per the title I was referring to molybdenum disulphide, in this instance the LM mos2 additive in a carrier oil.

Does that make much (or any) practical difference?

 

[Olas]

Originally Posted By: weasley
Originally Posted By: MolaKule
To which type of moly are you referring?


Originally Posted By: Olas
Specifically MOS2 interactions with different base stock

Assuming Olas was being correctly specific about molybdenum disulphide, rather than using "MOS2" as a proxy for "any old molybdenum additive".


+1 for reading the question in its entirety and responding appropriately