Simple Explanation of ZDDP Synthesis

MolaKule

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Synthesis (the chemical recipe for making this synthetic substance) of zinc dialkyldithiophosphate (ZDDP) consists of two stages.

1) phosphorus pentasulfide (P2S5) is reacted with an alcohol (usually isooctyl and or isopropyl)) to give dialkyldithiophosphoric acid, or DDP acid.
2) the acid is then neutralized by zinc oxide. Hence, ZDDP.

The resulting product is then heated to drive off any H2O and is filtered.

By changing reaction conditions such as rate of stirring, reaction pressure, neutralizing process, the order of addition of starting materials, and the types and amounts of alcohol, P2S5 and ZnO, various flavors of ZDDP can be produced.
 
Thanks MolaKule.

ZDDP seems to be a fairly useful oil add, it's an anti-wear agent to protect the metal, an antioxidant to protect the oil, and now it's found to strongly quench LSPI. Sure the Phos has exhaust cat poisoning issues.

With GF-5 oils you see 650 to 800 ppm Phos levels, while with Euro grade oils you often see 1000 ppm Phos levels and with HDEO maybe 1100 to 1200 ppm Phos (+100 ppm for the zinc levels).

If a new set of PCMO oil specs were realeased that had only performance levels to achieve, not chemical limits, what Phos & zinc level would you formulate around ? At least as a starting point before you tested and refined your blend.
 
Originally Posted By: SR5
Thanks MolaKule.


...If a new set of PCMO oil specs were realeased that had only performance levels to achieve, not chemical limits, what Phos & zinc level would you formulate around ? At least as a starting point before you tested and refined your blend.



If cost were not so much an issue, I would use a two-tier AW system consisting of
a ZDDP treatment level yielding 350ppm phos and 400ppm of zinc, with an AW ester.

I have an experimental oil I developed some time ago with 300ppm phos and 350ppm of zinc with that special AW ester and the results showed very low wear in three test engines. When the cost of that special AW ester comes down, I think the formulation will be more marketable.
 
Wow !! ... How interesting.

Could you tell us any more about the anti-wear ester. Low or High molecular weight ? Polar or non-Polar ?

Only if you are allowed to speak about it.
 
Originally Posted By: MolaKule
Synthesis (the chemical recipe for making this synthetic substance) of zinc dialkyldithiophosphate (ZDDP) consists of two stages.

1) phosphorus pentasulfide (P2S5) is reacted with an alcohol (usually isooctyl and or isopropyl)) to give dialkyldithiophosphoric acid, or DDP acid.
2) the acid is then neutralized by zinc oxide. Hence, ZDDP.

The resulting product is then heated to drive off any H2O and is filtered.

By changing reaction conditions such as rate of stirring, reaction pressure, neutralizing process, the order of addition of starting materials, and the types and amounts of alcohol, P2S5 and ZnO, various flavors of ZDDP can be produced.

What is the end game in producing the various flavors? Solubility in different oils?
 
Originally Posted By: bigj_16

What is the end game in producing the various flavors? Solubility in different oils?


The ratios of zinc, phosphorus, and sulfur in ZDDP can be custom made.

The end game is that different flavors of the ZDDP ester can be used in different applications.
 
Originally Posted By: bigj_16

What is the end game in producing the various flavors? Solubility in different oils?


The ratios of zinc, phosphorus, and sulfur in ZDDP can be custom made.

The end game is that different flavors of the ZDDP ester can be used in different applications.
does zddp always comes with ester?
 
does zddp always comes with ester?

Phosphates in general, being molecules with alkyl and aromatic substituents, are considered esters of phosphoric acid. Esters are organic compounds that use alkyl groups in place of hydrogen. ZDDP is created when phosphorus pentasulfide is reacted with one or more alcohols (alkyldithiophosphoric acid) and then neutralized (in varying amounts) with zinc oxide. ZDDPs with lower amounts of zinc oxide still have rather acidic properties which aids in its anti-wear properties. For this reason, most all ZDDP you would encounter in engine oils could be considered an acidic ester. More zinc oxide can be added to further neutralize and even overbase ZDDP, which can boost the anti-oxidant qualities, but hurts the anti-wear performance.
 
does zddp always comes with ester?
ZDDP doesn't come with esters. It IS a synthesized ester.

See section,

Section II: Synthetic Base Oils group IV and V​


in

https://bobistheoilguy.com/

A Review of Mineral and Synthetic Base Oils​


"...For example, a very useful ester in additive chemistry is the ZDDP molecule, whose function is as an Anti-Wear (AW) and Oxidation Inhibitor (OI). Members of the zinc dialkyldithiophosphate category are substances prepared by reacting phosphorous pentasulfide (P2S5) with one or more primary or secondary C3-C10 branched or linear alcohols to form the phosphorodithioic acid ester. The only exception is the alkaryl dithiophosphate where the alcohol moiety is tetrapropenylphenol. The dithiophosphoric acid ester is further diluted with 10-15 wt-% highly refined lubricating base oil (typical CAS #s 64742-54-7 and 64741-88-4) before it is neutralized with zinc oxide. The oil acts as a solvent in the neutralization reaction, manages the viscosity of the final product and improves consistency. The zinc complex that is formed upon neutralization is not a salt in the traditional sense, since the Zn-S bond is more coordinate covalent in character than ionic. (American Chemistry Council Publication 210-144870). There are about 15 versions of ZDDP chemistry.

In fact, many other additive chemistries are esters or in an esterified form..."
 
ZDDP doesn't come with esters. It IS a synthesized ester.

See section,

Section II: Synthetic Base Oils group IV and V​


in

https://bobistheoilguy.com/

A Review of Mineral and Synthetic Base Oils​


"...For example, a very useful ester in additive chemistry is the ZDDP molecule, whose function is as an Anti-Wear (AW) and Oxidation Inhibitor (OI). Members of the zinc dialkyldithiophosphate category are substances prepared by reacting phosphorous pentasulfide (P2S5) with one or more primary or secondary C3-C10 branched or linear alcohols to form the phosphorodithioic acid ester. The only exception is the alkaryl dithiophosphate where the alcohol moiety is tetrapropenylphenol. The dithiophosphoric acid ester is further diluted with 10-15 wt-% highly refined lubricating base oil (typical CAS #s 64742-54-7 and 64741-88-4) before it is neutralized with zinc oxide. The oil acts as a solvent in the neutralization reaction, manages the viscosity of the final product and improves consistency. The zinc complex that is formed upon neutralization is not a salt in the traditional sense, since the Zn-S bond is more coordinate covalent in character than ionic. (American Chemistry Council Publication 210-144870). There are about 15 versions of ZDDP chemistry.

In fact, many other additive chemistries are esters or in an esterified form..."
can it be determined how many of esters (in percentage) when zddp is present?
 
can it be determined how many of esters (in percentage) when zddp is present?
I am not sure I understand your question. Again, ZDDP IS an ester and different ratios of the three atoms can be produced via synthesis.

Are you asking if analytically it can be determined how many different "types" of ZDDP esters may be present in a formulation?
 
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I am not sure I understand your question. Again, ZDDP IS an ester and different ratios of the three atoms can be produced via synthesis.

Are you asking if analytically it can be determined how many different "types" of ZDDP esters may be present in a formulatain esters 5

I am not sure I understand your question. Again, ZDDP IS an ester and different ratios of the three atoms can be produced via synthesis.

Are you asking if analytically it can be determined how many different "types" of ZDDP esters may be present in a formulation?
It is
 
I am not sure I understand your question. Again, ZDDP IS an ester and different ratios of the three atoms can be produced via synthesis.

Are you asking if analytically it can be determined how many different "types" of ZDDP esters may be present in a formulatain esters 5
it is said that a lubricant can only contain maximum 5% of its volume. so if a lubricants have, let's say, 2000 ppm of zddp, how much esters in it?
 
it is said that a lubricant can only contain [a] maximum 5% of its volume.
Who says this is the case and where did you get this information? A maximum of what?

Howe said:
so if a lubricants have, let's say, 2000 ppm of zddp, how much esters in it?
If it is a single ZDDP type, then it will have 2000 ppm of ZDDP ester. If it has multiple ZDDP types, then one has to do an iterative calculation.

Through a complex and costly series of analysis, it can be determined if different types of ZDDP esters are present.
 
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Who or what states this 5% ester figure? What is your source?
based on common discussion around lubricants enthusiast from my group, if higher than 5% base oil will deteroriate, that was my fellows said
 
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