Home Cosmetic Science Talk Formulating How do I use liquid carbomer to thicken my product?

  • How do I use liquid carbomer to thicken my product?

    Posted by Heath0o7 on April 6, 2024 at 4:18 am

    Hi all,

    I’m making a facial Cleanser with a pH between 4-5. The ingredients are:

    Water

    1% liquid carbomer

    0.2% GLDA

    Sodium lauryl glucose carboxylate

    Glyceryl oleate & coco glucoside

    Sodium lauroamphoacetate

    Phenoxy & EHG

    Sodium benzoate & Potassium Sorbate

    Fragrance

    I added a drop of baking soda to the water first to increase the pH to 8. Then I added the liquid carbomer and GLDA then added it into the surfactants when I lowered the pH to 4.5 the cleanser didn’t thicken. I’m not sure why, I’ve never worked with a liquid carbomer before. I’ve waited for few days and the cleanser is still runny. Where do you think I went wrong?

    Heath0o7 replied 7 months, 1 week ago 4 Members · 9 Replies
  • 9 Replies
  • Perry44

    Administrator
    April 6, 2024 at 2:52 pm

    Well one thing is that Carbomer doesn’t work very well with electrolytes like sodium benzoate. Also, you should neutralize Carbomer at the end, not at the start.

    • Heath0o7

      Member
      April 6, 2024 at 10:06 pm

      I see, would you recommend using either liquid germal plus or parabens instead of sodium benzoate? As for neutralizing the Carbomer, do I increase the pH at the end then decrease it to 4-5 and that should thicken it?

  • chemicalmatt

    Member
    April 8, 2024 at 12:21 pm

    I think you need to more clearly define what exactly is “liquid carbomer”. There are many acrylate liquid rheology modifiers, most are 30% activity, and some are geared towards thickening surfactant systems. Others are not. If you are using one of the 30% acrylics suitable for your shampoo formula, then 1.0% w/w (0.30% solid) is far too short. Start with 3.50% and go from there. I would not adjust the pH below pH5.0 either. None of these build well below that pH and without the acid salt preservatives (as Perry remarked) you won’t need to.

    • Heath0o7

      Member
      April 9, 2024 at 5:24 am

      I’m not sure what type it is, the supplier’s website only states that it’s an acrylate copolymer in its acid form, and the pH must be increased to thicken. I’ve emailed the supplier to ask what kind it is, I’ll see what they say.

      As to the pH of the product, 5 is fine. I’ve put 4-5 because of the benzoate, but I can use LG+ instead since benzoate doesn’t work well with carbomer

    • Heath0o7

      Member
      April 10, 2024 at 2:18 am

      The supplier says it’s a lightly cross-linked acrylic polymer with approx 30% active. That explains why it didn’t thicken

  • Microformulation

    Member
    April 10, 2024 at 7:10 am

    I would also suggest that you use NaOH rather than “baking soda” to raise the pH.

    As @Perry44 mentioned it is also not very electrolyte tolerant.

    If you read some of the Technical assets from Lubrizol, they suggest neutralizing to a pH of 8 or so and then reducing the pH to your final level.

    • Heath0o7

      Member
      April 13, 2024 at 11:43 pm

      Thanks for the tip! I did a test batch and neutralized it to pH 8 then reduced the pH to 5.3 and the thickness thinned out and became runny again. So I tried a different method, where I neutralized the carbomer in a separate beaker, and I added all the other ingredients in another beaker and adjusted the pH to 5.3. I then added the neutralized Carbomer and stirrer until it was well incorporated and that seemed to keep the thickens. It only thinned out a little, but it’s a lot better than the previous testing. Thankfully the remained the same which is good.

      • Microformulation

        Member
        April 14, 2024 at 11:01 am

        Look closely at your supplier’s documentation. Is it possible you are using a pre-neutralized Sodium Carbomer?

        • Heath0o7

          Member
          April 16, 2024 at 12:46 am

          It says the carbomer is in its acid (2.1-4.0) form which is why it’s liquid. I assume that means it’s preneutralized? It recommends increasing the pH to thicken it.

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