Home Cosmetic Science Talk Formulating General [Chemists] Changing from Triethanolamine to Potassium Hydroxide for pH neutralizer

  • [Chemists] Changing from Triethanolamine to Potassium Hydroxide for pH neutralizer

    Posted by sean9980 on December 15, 2020 at 5:18 pm

    I am converting over from using Triethanolamine to Potassium Hydroxide, since Potassium Hydroxide is quite stronger than Triethanolamine, is there a way I can make a determination on how much Potassium Hydroxide to add to water (10% Potassium Hydroxide/90% Water), to get the equivalent amount of Triethanolamine. I dont know how much stronger for example 200 mL of TEA is to say a 20 mL solution of 10%/90% Potassium Hydroxide as there its more Hydroxide Ions in the Potassium Hydroxide?

    sean9980 replied 3 years, 3 months ago 2 Members · 3 Replies
  • 3 Replies
  • chemicalmatt

    Member
    December 15, 2020 at 8:28 pm

    @sean9980
    I’ve used the standard commercial grade KOH which is 40% active solution at 1.4:1 (Synthalen K or Carbopol 940), at nearly a 1;1 replacement with TEA 99%. You may do the algebra and figure from there.  You may also sub with Trolamine 40% (still good & still legal) at 3.2:1 ratio. Trolamine is  the best to use when neutralizing carbomers within a cream or lotion or shave cream.    

  • sean9980

    Member
    December 16, 2020 at 3:39 am

    @chemicalmatt

    Alright so what your saying is you have 40% KOH/60% Water, and then your using it a ratio of 1.4g (solution) per 1g of carbomer? I guess that really depends on what else is in the product too that may be affecting the pH. But in my head that just seems strong.

    (6.24) pKb value of Triethanolamine
    (0.5) pKb value of KOH
    https://www.aatbio.com/data-sets/pka-and-pkb-reference-table

    Is there a way I can determine the pKb of a 40% Solutiuon? Does that even make sense?

  • sean9980

    Member
    December 16, 2020 at 4:15 am

    My goal is to dillute the potassium hydroxide enough so that basically I can add the same amount of KOH sol. as I did TEA sol, which was around 200mL for my given product

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