Thiocarbanates ?

[Steve in Seattle]

quote:

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Originally posted by BOBISTHEOILGUY:
As I am seeing this, The surface can only hold additives but to layer the additives with a base oil on top of it(attracted not just coating it) then it would defeat the purpose of the additives as a barrier lube(among other things).

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ok, I don't think you REALLY want to get into this one. Lets just say that yes... and no. The additive isn't the Mo ion/atom... its the Mo-containing molecule discussed above.

umm... ok, just a bit more, I promise to make it easy though:

The Mo ion is one of the more "fun" ions that O-chemists like to play with. It, along with some other Group B heavy metals, are capable of unholy levels of ionization (i.e. +6!!!) The more charged the ion becomes, the greater the chance of a chemical bond forming... and yes, when they DO form they are VERY strong. What we're talking about here is the binding energy of an ion.

The difficult trick is to remove enough electrons without forming bonds to regaents you DON'T want in the molecule... which would give you unwanted by-products. A good chemist/procedure is almost always judged by how efficient his process is, and how pure his final product is.

Check out some blank tapes some time in the supermarket and you'll see the massive dependance we have on heavy metals in making things happen. The VERY best tapes out there are made with metals that reach a +6 final design. Cromium (Cr) is another favorite metal for this use... and looks good on wheels too

big deal right? well... since Mo can be ionized so well (if done in the right series of reactions and purification) it can bind REALLY well with the other chemical groups in the molecule. This strong binding makes for short bonds, and a smaller and denser molecule... picture a ball bearing... which has nearly non-polar chains on the outside of it so it stays in solution (and doesn't settle out like a polar or charged Mo ion would

).

Having double bonds in a nutral metal-alkoid (the final Mo-containging molecule wouldn't be charged, but may be a bit polar) is always a good way to interact with other metals as well.

The organic chains keep it soluable, the thiocarbonates and the strong Mo bonding give it a slight polar nature to interact with the metal-crystaline structure of the cylinder walls, bearings, etc...

but that's just my best guess.

[ June 27, 2002, 05:00 AM: Message edited by: Steve in Seattle ]

 

[Steve in Seattle]

quote:

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Originally posted by MolaKule:
I surmise that Mobil's new Supersyn is using their newly developed esters to provide boundary friction modification (reduction) along with a powerful antioxidant (used in jet engine's, BTW) to make up for the reduced ZDDP (if any).

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I think Mola's onto something here. Typically, esters are good at making molecules "locally" polarized near the bonds themselves, but in long non-polar chains it usually isn't enough to impact the molecule's "mostly non-polar" nature.

Now if you chemically modified the chains to incorporate several di-esters (yep just like it sounds) you could start making the easters more affinitive to metals. Only problem is, makeing these consistently, and STABLE, is very difficult... at least by academic standards. The oil companies though are responsible for EASILY more than 3/4 of all O-Chem knowledge that mankind posses, they research THAT much. (if you could come up with a process to decrease byproducts from 10% to 9% you would be rich for life). If anyone can do it, and make it commercially viable, it would be an oil company... I'd be very interested in getting a full write up on the new SuperSyn... although I'd bet the only an outsider would see such a document (which deffiently DOES exist), would require corporate spying, they're NOT going to give up that much R&D.

[ June 27, 2002, 05:13 AM: Message edited by: Steve in Seattle ]

 

[Al]

Steve: Mobil says their new SuperSyn is a PAO and not an ester.

SuperSyn, a proprietary patented technology of ExxonMobil, is a high-viscosity PAO typically used at low treat rates to balance the viscometrics, shear stability and low temperature properties of a lubricant

Could the same principle apply?
Also if this new PAO is more viscous as claimed. It would seem that the chains are longer and would have to be less polar?? N0??

Again great information!

[ June 27, 2002, 07:30 AM: Message edited by: Al ]

 

[JTC]

The discussion of just what SuperSyn might be is fascinating, and I thank Steve & MolaKule for their insights.

What they say reinforces my early opinion that we have dismissed Mobil1 with SuperSyn too quickly, and without data, because the chemistry is new and not to industry standards. But -- ExxonMobil strongly emphasizes the SuperSyn antiwear properties, which would be stupid unless they have done the testing and have the data to back it up.

Bottom line -- they say its antiwear protection is better than any previous Mobil1. I'm inclined to believe them, until proven otherwise.

JTC

 

[MolaKule]

Al, not to interrupt your thread with SIS, but the majority base fluid for any Synthetic for the
last 15 -20 years has been PAO, with the addition of esters. Now Amsoil used di-esters for awhile but switched to a PAO/Polyol-ester as well, actually following Mobil's trend. As I recall, the di-esters were becoming very expensive and the supply had dipped (supply and demand).
In addition, the polyol ester class has better oxidation stability than do di-esters and so it was a natural to move away from di-esters. Now over the years since PAO's have been introduced, better PAO's have been developed by Mobil chemists and by Shubkin at Ethyl Corp. From my research, what Mobil is saying is that they have developed a better PAO and I tend to believe them.

The PAO/ester ratio has been fairly consistent for most synlubes, except maybe for Redline. [Redline implies they have a greater ratio of polol esters in their formulation.]

The PAO/ester ratio was chosen for best performance verses cost. Compared to mineral stocks, the PAO provides extend low temperature and high temp performance (higher VI) and better oxidation resistance.

However, PAO's don't keep seals pliable, so they add esters (mainly polyol esters) to balance out the formula and allow seals to swell (a very small amount). Polyol esters (and thier new brothers and sisters) also increase the VI further and because of their polar qualities, have "affinities" to metals and particulate matter (sludge).

Due to the wide VI and natural cleanliness of the Pao/ester formulation, fewer additives are needed. Fewer additives means there are fewer chemicals to convert into sludge. So synth
base fluids rarely oxidize, but their additves can.

Now, introduce a high-polar surface film that reduces boundary friction when high temps and high loads are present, such as ZDDP or MoTDC, and you have a combo that offers the best of both worlds. Not PERFECT, but better than Group II mineral oils and cheap additve packages alone.

Now comes along the new EOP (liquid gas) synthesized hydrocarbon stuff from Pennzoil, and Group III (mineral-based) fluids and we have a very interesting situation. (I think in this vane, Vavoline's Maxlife and Scheaffer's are on the right track). Maxlife is Group III with additives and an FM of Moly, Schaeffer's appears to be Group II, PAO (for low temp pumpability and extend VI), and an additive packeage with MoTDC as well.

Which fluid comes out on top, I believe, will be determined by informed motorists, their analysis results, and the PERCEPTION of what these fluids can do.

So we live in exciting times!!!

 

[MolaKule]

Steve (and anyone else),

I can post the reference to the exact paper I referring to if interested.

 

[Ron]

Hi guys,
I know I don't belong here,however, the chemical soup talk is amazing. As the mystery continues, I'm surprised some of the more obscure oil companies have not pushed the quantifiable advantages to sell to the masses.Why all this maybe this or that.How about Castrol Syntec?
Sorry to bring down the lofty dialog.
Ron

 

[MolaKule]

Here is swipe from Terry's Analysis of Mobil's 15W50 from a post of June 13th, in the
Oil Analysis section.

"Kev99, The only thing that really stands out to me is the lower levels of Zinc,Phos,Magnesium,up to
50% decline from earlier levels which is consistent with new formulations. Moly surprises me as does
elevated calcium. Pipes are rusty at the plant where its blended. The esters used are invisible to this
test. High TBN with low organometals reflect "trick" esters being used as add or base oil is being
stressed to function as both. The proof will be in the usage and getting a sample drawn in the field.
Boundary layer lube depends on ester Ep and can be damaged in severe cases as bob has
demonstrated(disclaimer) unscientifically. You guys that hate moly M1 is using it, gee must be
something to its capabilities!"

Please note the following -
"The esters used are invisible to this
test. High TBN with low organometals reflect "trick" esters being used as add or base oil is being stressed to function as both."

I think this verifies my thesis.

 

[MolaKule]

"And BTW even though I do use Mobil now-I am really completely neutral on which the best oil is. I just want to learn and find the best."

I think that's why we're all here. And if we keep an open mind, we may find the silver chalace, or at least a low-cost brass cup. [Point - they both serve the same purpose].

The flash point is primarily determined by high-energy molecules in the formulation
(IE> additive package) and does not necessarily correlate (equate) to the base oil's oxidation stability.

I have a Fire Resistance-Flash Point chart from the STLE and it compares various BASE FLUIDs:
Here is how they rate.

1 = Lowest, 4 = Best:

1. Mineral Oils, polyisobutenes(lube thickeners), Polyalphaolefins(PAO), alkylated aromatics, Rape seed oils, PAMA/PAO-Cooligomeres(usually a thicker type of PAO).

2. Polyalkyleneglycols(PAGS), polyphenol ethers(very hightemp lubes for space and military), di-esters, polyol esters(mainly TMP), silahydrocarbons(a silicone-based hydrocarbon).

3. Silicone oils, dialkycarbonates.

4. Perflouralkyethers(ultra high-temp lubes for tanks, SST's, rocket turbine pumps), Chloroflurocarbons.

Now, you would expect the flash point of PAO's to be close to mineral oils since PAO is a "synthesized" hydrocarbon.

However, the oxidation resistance of base oils goes like this:

(Scale - 1 lowest, 5 best):
1. Mineral Oil
2. PAO
3. Alkylated Aromatic (Used in artic oils)
4. di-esters
5. Polyols Esters

Now let's say I mix a cheap additive component into the expensive polyol ester that flashes at the same point as the base mineral oil; the epensive polyol ester may then have a flash point only slightly higher than the mineral oil, because it has an additive molecule that has a low-temperature threshold, high energy molecule in it.

The point is this, a number of factors determine oil quality.

Let's say you and I concentrated on formulating the Flash Point, point, and forgot to add MoTDC, ZDDP or other suitable friction modifier for high-temp, high-load situations.

What would we have -
We would have a high-temp, no-flash oil that allowed an engine to wear out in 40,000 miles or less.

Here is what I look for in an engine oil(not necessarily in this order, mind you):
1. High oxidation stability (good base oils).
2. High level of friction modifiers (ZDDP AND/OR MoTDC[moly], or esters).
3. Viscosity (for temp range of operation). My preference is for a narrow grade range in summer(10W30), wide(r) range in winter(5W30).
4. Low sludge deposits (high dispersant/detergency).
5. Low deposits (and low piston ring and low intake valve deposits, [low level of additives]).
6. Driving habits (drive like hades or little old lady; highway miles or short trips).
7. Cost. Do I want an extended drain interval with expensive lubes, or do I want to
change oil once a month with a cheaper lube? (Can a Chevy do the job or does it
take a Caddy, Mack Truck, or motorcycle)?
8. What does the oil analysis about all the above?

Propbably more than you wanted, but I hope this helps.

 

[MolaKule]

One other item I failed to mention:

Volatility - I prefer the volitility to be less than 13% and preferably around 6-8%.

 

[dragboat]

Quote:
And BTW even though I do use Mobil now-I am really completely neutral on which the best oil is. I just want to learn and find the best."

I came to try to find out if a PAO say for example Mobil 1 would harm the motor seals in a Korean built car engine in long term use of 10 + years which I think but not certain uses a silicone type seal through out the motor. I am still looking for the answer to it?

 

[Al]

Molakule: Thanks. That's the type of information I was looking for. It helps put things into perspective.

Dragboat. Interesting. My daughter has a Korean car-Daewoo. I'll see what I can dig up on the subject. My guess is that since Syns mirror mineral oil in a number of different composition seals with respect to swelling there would be no problem. I am aware of that from my former job as maintenance supervisor.

 

[GW]

MolaKule,

What do you consider to be a "low level" of additives? You are an Amsoil fan - do Amsoil formulations not contain a high level of additives?

[ June 27, 2002, 11:16 PM: Message edited by: GW ]

 

[Al]

Molakule:

"I can post the reference to the exact paper I referring to if interested."

I would be very interested.

hmmm... sorry, but one piece of information always leads to another question (for me). We see the new generation of oils...blends, Group II, Group II+, Group III and the SL oils appear to have higher flash points. I know that Shaeffer's flash points appear higher than some syns-including Mobil. Now I assume that it takes special additives to do this. Question is: Blends and Group II, and probably Group III base oils do not hold up as well over a prolonged time due to oxidation as compared to PAOs and Esters. Do these additives break down and after a prolonged period of time the flash point goes down?? Or putting it another way would the PAO be still able to function under higher sustained temperatures than a blended oil which might actually have higher flash points?? Thanks and sorry for all the questions

And BTW even though I do use Mobil now-I am really completely neutral on which the best oil is. I just want to learn and find the best.

 

[MolaKule]

Dragboat,
Modern formulations that contain PAO's as the only synthetic have been formulated to contain a small amount of seal-swell additive (I.E., Schaeffer's come to mind). I don't see a problem, even with the Korean designs. Look at it this way, the Koreans probably obtain their seals from the same suppliers as do the Americans and the Japaneese.

GW,
Amsoil's certainly contains a hefty dose of ZDDP A,B, but the other additives are minimal, especially the VII's, since the base fluids have a naturally wide VI range.