How to substitute triethanolamine in a syndet bar recipe?

[Anstarx]

I came across of this video about how to make a translucent syndet bar.
The process looked simple enough and I already have most of the materials on hand (gotta sub the surfactants tho), so I figured why not give it a try. One material I don't have and never used or heard before is triethanolamine. According to the author in another video where they made another syndet recipe, they bought all the materials as a kit (if my memory served me right) so they couldn't offer any help on explaining its purpose or substitution.

After researching a bit I found triethanolamine to mostly used as a pH neutralizer for acidic ingredients, emulsifier, stablizer, and thickener.
I also found that typically this ingredient should be used between 2.5-5% (for non-rinse off according to this) instead of the whopping 25% in the recipe above, which got me concerned. I tried to look up recipes containing triethanolamine and found it was also used in small amounts (example). Supposedly it also have a mild ammonia smell, which I imagine would be hard to mask with a big amount.

My question being: what could be the reason for the recipe to call for such a large amount of triethanolamine, and would it be possible to substitute with other materials, while maintaining the translucent appearance.
I'm thinking I can use polysorbate 80 to emulsify the fragrance oil (which may make the bar cloudy) and use a weak lye to adjust ph if it's too acidic, or use decyl glucoside as a part of the liquid surfactant, and sub the missing weight just with water.

 

[Quanta]

25% triethanolamine doesn't sound right. Maybe someone misread 2.5%.

Also, in that video, the way they show checking the pH is not right. A 10% solution should be made with distilled or deionized water, and the pH of the solution checked. Just putting a strip of pH testing paper against a wet bar is always inaccurate becuase you can't control the percentage of the resulting solution.

I think if you substitute the surfactants, you may end up with something that doesn't even need the pH to be adjusted, anyway. You would have to experiment. I make syndet shampoo bars and I never have to adjust the pH with anything, and the pH is always somewhere around 5.5 (10% solution, checked with a meter).
Keep in mind you might also end up with bars that aren't clear, if you make substitutions.

If I were you, I would take this question to the Chemists Corner forum, the people over there know their stuff when it comes to formulating. This particular question might be a little outside the realm of a soapmaker's group. I think you'll get more useful answers over there.

 

[justjacqui]

The triethanolamine is used to neutralize the Cocoyl glutamic acid and create Triethanolamine Cocoyl Glutamate.

It may be possible to substitute it with sodium hydroxide but this may not produce a clear product. It would also need to be calculated to determine the correct amount because it would not be a direct swap.

I have seen Triethanolamine at Making Cosmetics (US) and Trulux (Australia).

Where did you find Cocoyl glutamic acid?

 

[Anstarx]

25% triethanolamine doesn't sound right. Maybe someone misread 2.5%.

Also, in that video, the way they show checking the pH is not right. A 10% solution should be made with distilled or deionized water, and the pH of the solution checked. Just putting a strip of pH testing paper against a wet bar is always inaccurate becuase you can't control the percentage of the resulting solution.

I think if you substitute the surfactants, you may end up with something that doesn't even need the pH to be adjusted, anyway. You would have to experiment. I make syndet shampoo bars and I never have to adjust the pH with anything, and the pH is always somewhere around 5.5 (10% solution, checked with a meter).
Keep in mind you might also end up with bars that aren't clear, if you make substitutions.

If I were you, I would take this question to the Chemists Corner forum, the people over there know their stuff when it comes to formulating. This particular question might be a little outside the realm of a soapmaker's group. I think you'll get more useful answers over there.

Thank you, I totally forgot chemist's corner exists for a second hahaha. That's a great advice!
I figured the pH testing paper isn't very precise so I plan to invest in a pH meter not just for this project but for my shampoo bar as well.

The triethanolamine is used to neutralize the Cocoyl glutamic acid and create Triethanolamine Cocoyl Glutamate.

It may be possible to substitute it with sodium hydroxide but this may not produce a clear product. It would also need to be calculated to determine the correct amount because it would not be a direct swap.

I have seen Triethanolamine at Making Cosmetics (US) and Trulux (Australia).

Where did you find Cocoyl glutamic acid?

I'm not going to use Cocoyl glutamic acid. I went to check the shop where the video author said she bought the kit from, and they only have cocoyl glutamic acid in the kit, not sold seperately. Couldn't find it anywhere I buy my supplies from.
Since my goal is mainly to make a gentle syndet bar,I will sub it with Sodium lauroyl glutamate which I can get from my local supplier.
My supplier also carries Triethanolamine at a reasonable price but I would love to avoid another one-use ingredient in my cabinet.
I would love the end product to be clear, but if it's not, I will still be fine with that.

 

[justjacqui]

If you are not going to use the cocoyl glutamic acid you will not need triethanolamine as there will be no need to neutralize it. The sodium cocoyl glutamate is already neutralized but probably won't be clear.