SUB NaOH with TEA - Cosmetic Science Talk

SUB NaOH with TEA

How much TEA would I use to substitute for .5 oz. of NaOH?

I've tried to look this up but could not find the answer.  I do know the ratio between NaOH and KOH which is 1.4 :D  Sometimes if you don't know the right question to ask you'll never find the answer!
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  • The weight ratio of TEA/NAOH  is 3.73: so on a weight basis for 0.5 ounces of NAOH use 1,87 ounces of TEA.
  • You will not have the same results by changing NaOH with TEA based on their molecular weight.
  • TEA soaps do not behave precisely the same as sodium soaps, or potassium soaps, for that matter. Whenever you change the base, you will change the product characteristics.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • Thanks everyone for their input!  Bobz really hit the nail on the head about TEA soaps and their comparison to potassium and sodium soaps!  A change in the characteristics is what I am seeking and knowing that the "positioning" of TEA in most of the popular brands ingredients list indicates to me that I need to up the percentage of TEA in my shaving cream formula very slightly above the NaOH percentage to give it the "cushion" or creaminess that it needs for shaving cream and to agree with the list.

    I'm thinking that not only upping the percentage of TEA in the formula is what is needed but doing it as a new first phase will be the best way to accomplish it.  By starting with the Stearic Acid and TEA first, creating a phase to just saponify that then going on to adding it to the other two oils in a second phase in which I add the other two bases, KOH and NaOH and adding that to the oil and TEA STEARATE in increments as I have just learned to do should help this to work!

    1 part TEA to 2 parts STEARIC is what is needed plus a little extra STEARIC (or slightly less TEA) should give me the creaminess of lather and cushion I need.  It still might be a balancing act with the oil/lye phase and the TEA STEARATE phase.  I did read that 5% was the limit for TEA usage (may not be true...) but I certainly don't need to go there!  Thanks again for your help!  I looked all over the place for an SAP value for TEA but couldn't find it.
  • edited August 9
    You might also want to look at AMP and/or AMPD as neutralizing agents:

    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • edited August 14
    I did finally manage to figure out how to replace some of the NaOH with TEA in my formula.  By calculating just the NaOH percentage of this formula separate from the KOH percentage and determining the percentage of each of the three oils/fatty acids (Stearic, Myristic, Coconut oil) that make up that NaOH percentage, then removing just 1% of the Stearic Acid and recalculating the NaOH for that portion, I was able to keep the oil phase total exactly the same size and now saponify that 1% of Stearic Acid with an additional 0.5% of TEA and thereby slightly reducing the NaOH without changing the oil phase percentage at all and with a minimal change to the water percentage.

    I tried to saponify the TEA in a 33% solution in the heated stearic acid but I don't think that it actually is a benefit and would be better to include it in the NaOH and KOH portion and thereby get a better mixing of the formula.  I'll know more tomorrow when I get to see what it looks like in the beginning of the "curing" process!

    Bob, I'm not sure there would be any benefit to a neutralizing agent in this type of soap-based formulation... thanks!
  • I'm using the term neutralizing agent here as a synonym for saponifying agent - in other words, a base that will react with the fatty acids/oils in your formula to form soap.

    To get really technical, as I understand it, saponifying is the term used when describing what happens when a base is mixed with a triglyceride, since there are two separate reactions taking place. Neutralizing, on the other hand, is used to describe what happens when an already existing fatty acid reacts with a base. Since you have a mixture of fatty acids and triglycerides, I think either term would be correct.

    Metal Hydroxides and Amines have both long been used for this purpose. Each chemical will have a somewhat different effect on your formula. If Triethanolamine helps your formula, then it's not much of a stretch to think that one of the Angus amines would also help.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • edited August 15
    BobZ,  Thanks so much for your reply!  I always appreciate it when I can learn something new!  As you probably know, I started out as "soapmaker" but learned very quickly how valuable having a "cosmetic chemistry" approach would be and how it would benefit me more!  I certainly knew about "saponification" and had some awareness of "neutralizing" but your explanation gives clarification in it's comparison of the two!

    I will take a longer look at the amines mentioned and see if I can find any examples of it in a shaving product.  I do have to be careful of expenses and also have to be aware of companies minimums which is one reason I have not changed over to replacing "coconut oil" with "coconut fatty acids"....yet!  My first attempt at replacing NaOH with TEA didn't come out as well as I had hoped and maybe I'll try a larger percentage of TEA as I have seen a few formulas that have replaced the NaOH and are in the .3-.35 range rather than being closer to 1.0% as it is in mine and in others.  So few examples of TEA use in lather shaving cream formulations which doesn't help!  Thanks again for your input and explanation!  It is appreciated!

    David
  • I'm coming back to this because I have found some conflicting information regarding the amount of TEA and Stearic Acid to combine to create TEA Stearate.  I was under the impression that 1 part of TEA would completely saponify 2 parts of Stearic Acid and found several formulas that agreed but went even further saying that 3 parts of Stearic and 1 part of TEA would work better because you would be sure to achieve full neutralization this way.

    I just found a listing in an old Cosmetic Chemistry book called "Modern Cosmetics" that says:

    Shouldn't that be "triethanolamine (25%) to melted stearic acid (75%)???

    I may try making Tea Stearate and adding it to the oil phase to "melt" as was suggested by a couple of formulas...  never ending battle here...
  • Well, what does stoichiometry say about the ratio? 1:2.85 should be correct.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • Belassi, I was told by Kevin Young, a cosmetic chemist:
     
    "The stoichiometric relationship for making TEA-Stearate is 2:1 stearic acid to 99% TEA."

    LOL, so which is it?  :p

  • Check it yourself.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • I did and came up with several different answers which is why I asked the question.
  • All you need to do is Google the molecular weight of each one and it will be very obvious. Remember 1 mole neutralises 1 mole giving 2 moles of product.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • So, I looked up the molecular weight of

    Triethanolamine
    : Molecular Weight:

    149.19 g/mol



    and Stearic Acid: Molecular Weight:

    284.484 g/mol

    Pssst!  Belassi!  I only took Chemistry 1 in High School and that was in 1973...





  • edited September 16
    Ah. I can see where the confusion is coming from now. Using the abbreviation TEA is a problem because it is also used for triethylamine which has a mole weight of 101.2 ... whereas triethanolamine is 149.2
    Stearic acid is 284.5 and so the correct procedure is to add 284.5g of acid to 149.2g of base. (1 mole of each) A ratio of 1.9 to 1, within 2% accuracy. 
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • Clive,  I've been on the computer for two hours trying to figure this out!  So, I got the numbers right..but I just didn't know what to do with them but I did divide 284.2 by 149.2 but didn't understand how the 1.90 related... having a "duh" moment!

    So, what I gather is that some formulators will add an extra part of Stearic Acid so that the Triethanolamine become the limiting reactant in the formula!  Others have mentioned slightly reducing the amount of triethanolamine in proportion to the stearic acid used to again make the Triethanolamine the limiting reactant in the formula.  The excerpt I posted from the Modern Cosmetics book from the 1930's made me think that either it was error in posting or in the 1930's 99% triethanolamine may not have been available or commonly used!?

    Anyway, I got my answer and I appreciate your help!  As an addendum, one of the biggest problems I have had with this shaving cream formula is determining whether I should be adding the Triethanolamine Stearate to the formula or replacing some of the fatty acids and bases with it!  Now, I am thinking to just add the Triethanolamine Stearate to the formula and recalculate the rest.  Finding examples of formulas that are "soap based" without the addition of surfactants and using NaOH, KOH and TEA has been a real problem!
  • Part of your problem is that to my knowledge, there are no calculators available that deal with variable amounts of the different possible bases in a saponification reaction. I may create an Excel version if I feel motivated enough.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
  • That would be great as I have looked for such a program and found nothing!  The other problem I am having is that I am determined to follow the ingredients listing of the British Shaving Cream companies, many of whom have these exact ingredients in this exact order:

    Water, Stearic Acid, Myristic Acid, Potassium Hydroxide, Coconut Acid, Glycerin, Triethanolamine, Sodium Hydroxide, Fragrance, preservative.

    Following the recommendations of Poucher and Thomssen for the ratios of ingredients required to create a shaving cream with certain characteristics, I have come so close but mine read:

    Water, Stearic Acid, Myristic Acid, Potassium Hydroxide, Coconut Acid, Glycerin, Sodium Hydroxide,Triethanolamine, Fragrance, preservative.

    Since Trienthanolamine Stearate helps to create a "creamier" lather and what is called "cushion".  I am seeking to create a product as close to the British Shaving Cream companies as is possible but TEA Stearate also seems make the cream more firm and pasty.  It's a balancing act and after 20 batches in the last three months, I'm eager to find the right formula!  I'm so close but not there yet! 






  • I see palmitic acid as a very common ingredient.
    Design of anti-aging creams, gels, and serums; shampoos; and therapeutic cosmetics. In-house label and box design capability.
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