Home

Esters, General

Posted By: MolaKule

Esters, General - 08/22/02 01:06 AM

Esters, in organic chemistry, are compounds formed (along with water), by the reaction of acids and alcohols. Because this process is analogous to the neutralization of an acid by a base in salt formation, esters were formerly called ethereal salts. This term is misleading because esters, unlike salts, are not ionized in solution (see acids and bases).

Esters can be formed from both organic and inorganic acids. For example, the simple ester ethyl nitrate may be obtained from ethyl alcohol and nitric acid (an inorganic acid), and the ester ethyl acetate may be obtained from ethyl alcohol and acetic acid (an organic acid). Another method of preparing esters is to employ not the acid itself but its chloride. For example, ethyl acetate may be prepared by the action of alcohol upon acetyl chloride, the chloride of acetic acid. Another important method of preparation is by the reaction of the silver salts of acids with an alkyl halide (usually iodine). For example, ethyl acetate may be prepared from silver acetate and ethyl iodide.

Esters are broken up by the action of water into their component acids and alcohols, a reaction greatly speeded by the presence of acids. For example, ethyl acetate is broken up into acetic acid and ethyl alcohol. The conversion of an acid into an ester is termed esterification. The reaction between an ester and a metallic base is known as saponification (see soap). When the decomposition of an ester occurs upon its reaction with water, the ester is said to be hydrolyzed.

The esters of organic acids are usually colorless, neutral liquids, pleasant-smelling and generally insoluble in water but readily soluble in organic solvents. Many esters have a fruity odor and are prepared synthetically in large quantities for commercial use as artificial fruit essences and other flavorings and as components of perfumes (see essential oils).

All natural fats and oils (other than mineral oils) and most waxes are mixtures of esters. For example, esters are the principal constituents of beef fat (tallow), hog fat (lard), fish oils (including cod-liver oil), and flaxseed oil (linseed oil). Esters of cetyl alcohol are found in the head oil of the sperm whale, and esters of myricyl alcohol in beeswax. Nitroglycerin, an important explosive, is an ester.

Esters such as amyl acetate (banana oil), ethyl acetate, and cyclohexanol acetate are the principal solvents for lacquer preparations. Other esters, such as dibutyl phthalate and tricresyl phosphate, are used as plasticizers in lacquers. Amyl acetate is employed as odor bait in grasshopper poisons, and several of the formates are good fumigants. Esters also have an important function in organic synthesis.
Esters have important medical uses. Ethyl nitrite is a diuretic and an antipyretic. Amyl nitrite is used in the treatment of asthma and epileptic convulsions as an antispasmodic. Nitroglycerin and amyl nitrite both cause blood-vessel dilation thereby lowering blood pressure. Ethyl chaulmoograte has been used in the treatment of leprosy. Dimethyl sulfate (often used in organic synthesis as a methylating agent) and diethyl sulfate are extremely dangerous in vapor form and must be handled cautiously.

Many additives are in the form of esters when added to the formulated oil, but carboxylic acid esters (and the sub-classes di-esters and polyol esters) are contained in fully formulated synthetic oils. Most Group III oils and PAO based oils need a small amount of ester for seal swell, increased detergency, better oxidative stability, greater VI, and increased additive solubility.

The two most common polyol esters for automotive applications are TMP (trimethylpropane) and DPE (DiPentaerythritol) PE (Pentaerythritol) or similar. Some di-esters are used in non-detergent compressor fluids, and NEO-Oil uses these as bases exclusively.

There are over 175 di-esters and over 250 polyol esters of last count.

A good overall description of esters for ester lubricating fluids can be found at:
http://www.hatcocorporation.com/pages/about_esters.html

Added: Carboxylic Acid Esters

Esters are created by a process called, "esterification," the reaction of alcohols or phenols with acids. For example, react tricresyl phosphate acid with an alcohol called n-butyl alcohol and the result is an ester product called "Neutra," a fuel system and crankcase cleaner.

A carboxylic acid is a general term for a number of acids with a specific molecular arrangement. A carboxylic ester can be made with one of over 120 carboxylic acids. Carboxylic acids may be used to form dibasic esters (as in NEO base oils)and polyol esters such as TMP and PE, which are used in Amsoil and Redline oils, respectively.

Hydroxyalkyl Carboxylic ester is actually a "lactone," a cyclic ester made from the salt of a hydroxy acid.

This ester is used in many motor oil formulations that contain PAO(s) and is used to increase the VI, cause a slight seal swell, adds miscibility (mixibility) for additives, increases oxidative stability, and acts as a Friction Modifier.

[ January 04, 2003, 12:37 AM: Message edited by: MolaKule ]
Posted By: dickwells

Re: Esters, General - 08/22/02 07:07 AM

Wow, a one man organic chem data base. It takes me back to 1962, I guess I was not as asleep as I thought because a lot of that stuff sounds familiar. Keep up the good info. RW
Posted By: dragboat

Re: Esters, General - 09/17/02 11:49 PM

Would you mind writing a bit about Esters and the role they play in Automobile oil formulations?

How about somthing about the new Esters Mobil has developed and something more on the the EOP Synthetic in the works by Pennzoil?

Molakule deserves a forum given Xmas gift,like a years worth of oil or something along that line [Cheers!]
Posted By: Modaholic

Re: Esters, General - 09/28/02 11:26 PM

dont shoot me, but what do you think of lubegard bio tech engine protectant? thats a ester right?
Posted By: Terry

Re: Esters, General - 09/29/02 07:39 AM

I like Lubeguard products. They are primarily vegetable based esters. Their trans additive is good also but Auto-Rx does thesame thing at a lot lower cost at least here in Texas.

For a engine cleaning I would use Auto-RX for the bio based stuff.
Posted By: rob-the-oil-nut

Re: Esters, General - 02/12/03 08:56 AM

Golly MoleKule, that's a LOT of information. I for one do not know what line of work or educational background you have, though reading between the lines I can make a few guesses (assuming that info isn't a copy & paste from a chemistry CD-ROM) [Big Grin]
So, what oil do you use in your engine? How often do you change it?
If I recall right, you like Auto-RX. Is that correct? When I have my RedLine drained (it was just put in so that could be a while) I'd like to have a good cleaning, should I use plain or synthetic oil? I'm thinking of just doing a 700 mile cleaning oil. Should the filter and by-pass filter be replaced just before that? If I have a by-pass filter, should I replace the element at the time the RedLine is drained, or after the Auto-RX 300 or 700 miles is up? (I want to have the used filter sent to the lab) If I have a by-pass, how important is the plain spin-on filter?

[Big Grin] Always plan at least 11 months into the future [Big Grin] Only about 250 shopping days left before Christmas [Big Grin]
Rob
Posted By: MolaKule

Re: Esters, General - 02/12/03 12:38 PM

rob,

The information was drawn from my notes which was a compilation of research and lab work over the years.

On another thread I recently posted the oils I use, so you might want to do a search. I use some oils that are proprietary and are in development.

For your situation, I would continue to use Redline, and Auto-RX in the maintenance dosages and your engine should be clean. ARX does use some cleaning esters that are not contained in Redline.
Posted By: Cressida

Re: Esters, General - 03/27/03 12:20 AM

Note this link regarding vegt. oils :

http://biz.yahoo.com/rc/030324/science_oil_5.html

With this as the nest to last paragraph:

"The vegetable oil would replace certain additives in motor oil that are used to prevent, for example, corrosion or the buildup of residue that can damage car filters or spark plugs."
Posted By: MolaKule

Re: Esters, General - 03/31/03 05:50 AM

that last paragraph looks as if the jounralist need a few more words but was unable to generate the correct information.

Unless you have severe blowby or weird fuel, the last paragraph is non sequitur.
Posted By: MolaKule

Re: Esters, General - 08/05/04 02:26 PM

No base oil, when at room temperature, has a smell. All base oils come from the refinery water white and clear.

Now when heated, mineral oils have this faint sulfur smell, PAO's no smell, and Esters have this "fatty" smell to them, because they are made of fatty acids and alcohols. The only esters that have "fruity" smells are those used in cosmetics and pharmaceuticals. Esters used in motor oils have little smell to them.

Additives and "odor-fiers" is what gives a formulated oil its smell.
Posted By: FowVay

Re: Esters, General - 08/05/04 10:13 PM

I'm glad you mentioned this Mola because so many people were quick to denounce my comment that German Castrol was claimed to be a group 4 basestock (castrol's proclamation). The evidence that it HAD to be a ester was based simply on the smell.

It truly is the additives in the base fluid that give a oil its odor and color. Base oils that I've experimented with could pass for water before they get blended.
Posted By: Primus

Re: Esters, General - 08/07/04 07:57 AM

Esters oils are biodegradable by nature, but BIO oils are also esters based. Apparently the prefix Bio underlines a higher speed and a percentage of decomposition. What are type of esters usually used in Bio engine oils and what are their strong sides ? TYI.
Posted By: MolaKule

Re: Esters, General - 08/07/04 02:17 PM

Excellent point Primus.

Bio oils are indeed "natural" esters, which interest me very much as well, and presents an exciting way of weaning ourselves off petroleum-based feed stocks.

The term or prefix Bio or Bio-oil usually denotes an oil derived from living organisms, sch as plants or animals.

Some plant derived Bio-oils which may be used as lubricants are: {This list is NOT all inclusive since new bio-oils useful for lubrication are being discovered every day].

Peanut
Corn
Sesame
Soyabean
Walnut
Macadamia
Grapeseed
Sunflower
Canola (rapeseed)
Castor
Jojoba
Palm
Crambe
Coconut

BTW, canola is the term for genetically modified rape seed.
Posted By: labman

Re: Esters, General - 08/07/04 02:38 PM

I worked for years in the paint industry using vegetable oils, including many of those listed in the above table. We used vegetable oils because the unsaturated ones, when exposed to air, would oxidize and convert to solid films. Heat and metals would accelerate this process. Try pouring a few drops of your wife's cooling oil on a hot manifold. Not in any engine of mine, ever.

I don't have a problem soy diesel. Diesel fuel remains fairly cool until injected into the combustion chamber, and usually is used up long before it could cause problems. For long term storage, I would recommend a flush with conventional alkane based fuel.
Posted By: Brian Reid

Re: Esters, General - 08/07/04 02:49 PM

quote:
BTW, canola is the term for genetically modified rape seed.
Canola is the term for any of several varieties of the rape plant having seeds that contain less than 2% erucic acid.

http://www.yaelf.com/aueFAQ/mifcanola.shtml

The low erucic acid rape plants originated naturally, in Saskatchewan, from seeds grown by
a farmer who had immigrated from Poland.

http://www.canola-council.org/pubs/originhistory.pdf

The low erucic acid made the oil edible (erucic acid levels in edible rape is limited to 2%). From this seed two strains trademarked as "Canola" were developed between 1958 and 1974 by two Canadian scientists, Baldur Stefansson and Richard Downey. They are generally known as the "Polish" (Brassica rapa) and "Argentine" (Brassica napus) strains.
Posted By: MolaKule

Re: Esters, General - 08/08/04 07:22 AM

OK, lets add two more to the list:

Some plant derived Bio-oils which may be used as lubricants are: {This list is NOT all inclusive since new bio-oils useful for lubrication are being discovered every day].

Peanut
Corn
Sesame
Soyabean -
Walnut
Macadamia
Grapeseed
Sunflower
Canola (rapeseed)
Castor
Jojoba
Palm
Crambe
Coconut
Safflower - a variation of sunflower, part of the sunflower family. Not used very much because of its naturally high levels of oxidants and short shelf life.
Meadowfoam - a very promising oil, similar to Jojoba in terms of high levels of natural anti-oxidants.

BTW, most of the oils from the major plant groups are genetically modified (with respect to natural plant species) to yield high oleic (high in 'unsaturated' fatty acid) contents.

In this new list, I have bolded those oils I believe to be the major contenders for formulation purposes in automotive applications.
Posted By: dropitby

Re: Esters, General - 08/16/04 12:59 PM

MoleKule said:react tricresyl phosphate acid with an alcohol called n-butyl alcohol and the result is an ester product called "Neutra," a fuel system and crankcase cleaner. You mean mixing these 2 chemicals and you get Neutra. Next is Lactone in both AMSOIL & NEO and finally which is the most expensive dibasic esters or Polyol esters. Thanks great stuff [bowdown]
Posted By: MolaKule

Re: Esters, General - 08/16/04 02:01 PM

quote:
react tricresyl phosphate acid with an alcohol called n-butyl alcohol and the result is an ester product called "Neutra," a fuel system and crankcase cleaner. You mean mixing these 2 chemicals and you get Neutra.
Actually, you get something similar to Neutra; this was a simplified example. Neutra is actually cresyl acid (different acid) reacted with n-butyl alcohol. Reacted is the keyword here. Just mixing the two won't get you Neutra or any other ester. There has to a be a catalyst involved in the reaction as well.
Posted By: Shannow

Re: Esters, General - 08/17/04 07:01 PM

Molakule,
is there a simple test that can be carried out to see if esters are present ?
Posted By: T-Keith

Re: Esters, General - 08/18/04 12:22 AM

I checked my bottle of Supercharger fluid. Ester(animal fat based) with some phospheric acid? I'll post a new topic with the actual bottle listings. Man that stuff stinks after use.
Posted By: MolaKule

Re: Esters, General - 08/18/04 05:48 AM

quote:
is there a simple test that can be carried out to see if esters are present ?
I have no knowledge of simple test that could carried out by a non-chemist.
Posted By: buster

Re: Esters, General - 08/18/04 07:19 AM

quote:
There are over 175 di-esters and over 250 polyol esters of last count
Amazing. So these oil formulators have a lot to chose from. It must be a task in and of itself in trying to pick the best choices. I mean look at Redline/Old Diester Amsoil/Motul and Delvac 1. They all used different esters and show different results. And then you have the additives interacting with all of this. Very cool. Chemistry is very interesting. [Cool]
Posted By: MolaKule

Re: Esters, General - 08/18/04 08:36 AM

Interesting and technically challenging.

See:

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=4;t=000361

[ August 18, 2004, 06:46 PM: Message edited by: MolaKule ]
Posted By: MolaKule

Re: Esters, General - 09/02/04 12:42 PM

The relative molecular mass (sometimes called "Molecular Weight") is the ratio of the average mass per molecule of an element or compound TO 1/12 the mass of a carbon-12 atom. I.E., it is equal to the SUM of relative atomic masses of ALL atoms that comprise a molecule.

Generally speaking, the higher molecular weight products of an oil show higher viscosities, but that only half of the story since the molecular "structure" also affects the molecular weight. Take the VII molecules of polymthylacrylates. These are high molecular weight structures that cause the formulated oil to become more viscous as temperature rises because of uncoiling at higher temperatures.

Ester may contain high or low molecular weight components as well, and may have KV's of 2 cST to over 100 cSt at 100 C. In esters, the structures are more important than molecular weight (except of course in determining final base viscosity).

When developing esters, particular attention is paid to ester structure. Short linear chains show better oxidative stability, whereas increasing the acid chain length of the molecule improves (decreases) the coefficient of friction.

This why Di- and Pentaerithyritol esters (PE's) are better (more stable) than Trimethylpropane (TMP) esters, and why TMP is better than Neopentylglycol (NPG) esters. The PE's have short chains of linear acid chains with make the ester more oxidatively stable and exhibit lower coefficients of friction.

If the ester is made from linear branched acids, the ester has higher flash points; increasing the molecular weight (making the ester molecule more compact) will also increase the flash point.

Representative esters:

Phthalates - Used mainly in air compressors; short fat molecule results in VI v.s pour point tradeoff.

Trimellitates - Short, branched esters that have high flash points and low volatilities and good thermal stability. Used when you need to leave a soft film behind.

Dimerates - Made from the acid of tallow oils and an alcohol (is three-branched); Has excellent lubricity and thermal and oxidative stability; used mainly in 2-stroke oils.

Polyols - SPE's, PE's, TMP's, TME's, and NPG's. Three or more shortchain but fat molecules. Polyols are generally more oxidative and thermally stable by 50 C over diesters and 150 C over petroleum oils. These esters have lower coefficients of friction than either diesters or PAO's.

By adding a polyol ester at least 5-10% to a PAO or mineral oil reduces base oil friction remarkably. So esters are natural Friction Modifiers.

Advanced esters can also BE USED AS VII improvers. Unlike long-chain polymers (such as methacrylates), complex polyols do NOT EXHIBIT the temporary loss of viscosity under forces exterted by shear, as in gears. Because complex esters are shorter chain molecules, they tend not to shear into smaller molecules.

Adding amine "backbones" to ester molecules allows them to have better antioxidant capabilities.
Posted By: nortones2

Re: Esters, General - 09/02/04 06:28 PM

Molakule: I have heard that esters have polar properties, whereas PAO and other lubricants have nil or small polarity. Is this correct? Further, are such properties, if they exist, uniform throughout the ester group?
Posted By: MolaKule

Re: Esters, General - 09/03/04 07:14 AM

All fluid materials have polar properties, some more than others.

From Most Polar (attractied to Metal) to least:
Esters
Mineral Oils
PAO's.

The majority of esters are very polar due their molecular nature.
Posted By: MolaKule

Re: Esters, General - 11/13/09 04:42 AM

Here are some very useful esters used in motor oils and gear lubes:

1. PHOSPHORODITHIOIC ACID, O,ODI-
C1-14-ALKYL ESTERS, ZINC SALTS 68649-42-3

Also known as ZDDP

2. 2-ETHYLHEXYL SEBACATE 122-62-3


Used as a seal swell agent, base oil, and friction modifier.
Posted By: MolaKule

Re: Esters, General - 11/13/09 05:27 AM

Here's another useful multifunctional ester:

1. PHOSPHORODITHIOIC ACID, O,OBIS(
2-ETHYLHEXYL) ESTER,
MOLYBDENUM COMPLEX 72030-25-2

Soluble Moly complex, AW/EP and antioxidant
Posted By: nucleardawg

Re: Esters, General - 11/14/09 06:21 AM

You mentioned Jojoba in the list of esters. Since it was posted on tonight I do believe that the Lubegard Bio Tech Engine Ptotectant is using that in it's formulation.
Posted By: MolaKule

Re: Esters, General - 11/15/09 02:57 AM

Lubeguard uses a number of oeleoesters (bioesters or derivatives of bioesters) in their mix.
Posted By: postjeeprcr

Re: Esters, General - 11/25/09 07:36 AM

Originally Posted By: nucleardawg
You mentioned Jojoba in the list of esters. Since it was posted on tonight I do believe that the Lubegard Bio Tech Engine Ptotectant is using that in it's formulation.


Hy-per Lube uses jojoba in their racing oil supplement formula which from what I have read on their site that the only difference from the regular oil supplement they sell is the jojoba oil in it.

Lots of great information MolaKule, as always. Have you been able to or would you test any of the new G Oil? It is made out of tallow, as I am sure you know.
Posted By: ac_tc

Re: Esters, General - 04/10/10 10:13 PM

Ok..
So now we now that esters belongs in oil.
Should i dope my HDEO ci+4 oil with lets say 20% redline?
Posted By: Wilhelm_D

Re: Esters, General - 04/11/10 03:34 AM

Originally Posted By: ac_tc
Ok..
So now we now that esters belongs in oil.
Should i dope my HDEO ci+4 oil with lets say 20% redline?


The effect is not linear - 5 to 10% is a useful and not too expensive addition. As the percentage goes up, the marginal utility decreases.

Also, Red Line is a blend.

In addition you can formulate a completely successful motor oil with no esters - you could use, for example, an alkylated napthlene to get many of the same benefits.
Posted By: ac_tc

Re: Esters, General - 04/15/10 04:22 PM

Redline is avail, the alky naphta isnt..
I think ill try the 5% mix.
© 2019 Bob Is The Oil Guy