Home Cosmetic Science Talk Formulating Stearic/palmitic acid soap

  • Stearic/palmitic acid soap

    Posted by nkpalaci on August 8, 2024 at 12:57 pm

    Hola!,

    I’ve been testing shaving creams for a while, none of them are worth it, and I found a patent on the forum for a classic cream formulated with stearic acid soap with NaOH and palmitic acid with KOH (link attached).

    I haven’t formulated soap many times, but I understand the procedure. What I don’t understand is how I can make a soap with only stearic acid and another with only palmitic acid.

    I didn’t find anything similar on the internet, my only help in this moment.

    Gracias for your interest and help! 🙂

    https://patents.google.com/patent/US2298019

    nkpalaci replied 3 months ago 2 Members · 2 Replies
  • 2 Replies
  • Aniela

    Member
    August 8, 2024 at 2:53 pm

    Hello,

    Not a soap-maker but bear with me, I’m bringing gifts😇

    You say “What I don’t understand is how I can make a soap with only stearic acid and another with only palmitic acid.” but they say in the patent “Experimentation has proved that the soap or cream containing the specified palmitic-stearic mixture, glycerin, and water, as disclosed in this specification”- plus the obvious NaOH/ KOH.

    On a older post (stick deodorant, but the theory applies), @Bobzchemist said “If you’re trying to make a solid stick, it would probably be easier to use Sodium Hydroxide and Stearic Acid. Heat your water/zemea mixture to no more than 85C, start stirring, add Stearic Acid, wait until it’s dissolved, add Sodium Hydroxide, mix 30 minutes while reaction completes, (it’s exothermic, so you will probably shoot up to 95C without heating further. If your starting water mixture is too hot, the extra heat from the reaction will make the batch boil - not a good thing) Add your other ingredients and cool down. Pour into sticks at about 60 - 70C” so I’d venture to say that if you replace the “zemea” with glycerin and follow the procedure, you’ll have your soap.

    Here’s the link to the old post, it might help https://chemistscorner.com/cosmeticsciencetalk/discussion/making-deodarant/

  • nkpalaci

    Member
    August 8, 2024 at 7:14 pm

    It’s not entirely clear to me why it was written in the last century, they have a different style haha. Among all the times he repeats the same thing, in one part he says “saponified palmitic acid and saponified stearic <div>acid being soaps of the class consisting of Sodium and potassium soaps, with from approximately 5 to 10 parts by weight of potassium Soap being present in said saponaceous portion to each”. I interpret that the saponization is separate, but I think it could very well not be, just that I’ve never read about it before, maybe it’s a risky task. I can’t understand how much % of the stearic / palmitic acid I could use, I don’t want to make a rock.</div>

    Anyway, your message with the forum thread is great!!

    I haven’t continued with the cream yet because I have to buy many materials at the same time, I live at the end of the world. I will try to update.

    Thanks!!

Log in to reply.

Chemists Corner