Home Cosmetic Science Talk Formulating SCI refuses to melt. Wrong surfactant combination?

  • SCI refuses to melt. Wrong surfactant combination?

    Posted by Anca_Formulator on December 10, 2023 at 12:50 pm

    Hi, I am new to surfactants. I am working on a solid cleansing/conditioning bar and my SCI simply won’t melt even after an hour…Here is my surfactant phase:

    SCI (tried both powder and prills): 30%

    SLSa (powder): 30%

    Plantapon LGsorb (Sodium Lauryl Glucose Carboxylate (and) Lauryl Glucoside: 14.5%

    My method is blend all three in a glass beaker and place in double boiler. Tried roiling boil with water high enough to be above contents of beaker, but not so high it splashes into it. Also tried heating it more slowly, I can’t seem to get it to come close to 75 C.

    This is a while lot of powder with little liquid surfactant, but these are the three I’d like to use for mildness and skin feel, though I’m open to substitutions.


    Please advise.

    Thank you!

    Anca_Formulator replied 1 year ago 2 Members · 2 Replies
  • 2 Replies
  • ozgirl

    Member
    December 11, 2023 at 4:32 pm

    The SCI only ‘melts’ to become a paste type consistency. It does not become a clear liquid.

    For best results try melting the SCI with only your liquid surfactant. Do not add the SLSA until after the SCI is melted. I remember reading (not sure where) that amphoteric surfactants (e.g. Cocamidopropyl betaine) work best to aid the melting of the SCI so you could try adding some amphoterics.

    This link might help more.

    https://www.windypointsoap.com/blogs/formulas/basic-shampoo-bar-formula

    • Anca_Formulator

      Member
      December 13, 2023 at 11:20 am

      Thank you so much! It really helps to know SCI won’t become clear.

      I had read somewhere as well just recently that amhoterics help, I tried cocamidopropyl betaine and it was a whole different story. I’ve been following Swift Crafty Monkey (Susan Barclay Nichols) for years 😉 In fact this surfactant phase was modeled on one of her formulas, where she also says she doesn’t understand why people have such a hard time melting SCI! The link you provided is to formulas from another ebook where I see she changed the method from melting all three together. Surfactants are a whole new world for me…lots to learn.

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