Home Cosmetic Science Talk Formulating How to decrease effects of fragrance on viscosity of bodywash?

  • How to decrease effects of fragrance on viscosity of bodywash?

    Posted by chem.ist on December 18, 2023 at 3:48 pm

    Hello,

    Im working on a body wash for a client and they loved the base formula. They chose a couple different premade fragrances to use and one of them decreases the viscosity of the body wash by a lot. They also want the fragrance at 2%. I had it at 1% originally and had the same issue with the same fragrance. The target is a rich creamy gel like The Body Shop Shower Cream, but it turns into a super runny liquid once I adjust the pH below 6.

    The main surfactant system includes sodium cocoyl glycinate, and CAPB (38% active material). Using acrylates copolymer at 12% as the main thickener.

    I tried premixing the fragrance with some CAPB before i add it at the end but it didnt work. I saw some people suggest using a solubilizer, any suggestions? All help is appreciated!

    Thanks!

    chemicalmatt replied 4 months, 2 weeks ago 5 Members · 9 Replies
  • 9 Replies
  • oldman20

    Member
    December 19, 2023 at 2:12 am

    did you try another thickeners in that formula?

    • This reply was modified 4 months, 2 weeks ago by  oldman20.
  • ketchito

    Member
    December 20, 2023 at 7:32 am

    I will ask the obvious first: did you make a sample without any fragrance, and adjusted the pH below 6 without any viscosity loss? I ask this, since many acrylate-based rheology modifiers need to be neutralized in order to work, and the lower the pH, the less neutralized polymer you’ll have in solution (and the lower the viscosity).

    Now, 2% of fragrance is a lot! Even 1% is quite high for a body wash. You could of course pre-mix it with a solubilizer prior to adding it to your main batch (polysorbate-20 or PEG-40 HCO), but I’d check first if the low pH for your product is what’s causing the viscosity drop.

    • chem.ist

      Member
      December 21, 2023 at 12:01 pm

      Yes! So the client has different fragrance options and all of them worked and did not decrease the viscosity even at a lower pH, except for one of the fragrances. This happens to be their favorite so I do need to figure it out. Ive been using the carbopol aqua sf1 with no issues at low pH but I will try their sf2 version to see if it works out. Without the fragrance the viscosity is perfect. With the other fragrances the visc is perfect. Just the one fragrance is messing everything up

  • chemicalmatt

    Member
    December 20, 2023 at 12:40 pm

    Once again @ketchito is on the ball. Not all acrylate copolymers are same. You are using a LOT there at 12% (all are 30% solutions) so the pH is a factor. We recommend using the range pH 6.0 - 6.5 with Synthalen W600. DO NOT add any extra salt since the CAPB carries 5% NaCl itself. You should only need half that level of acrylate thickener and it will accommodate the fragrance oil too, even though that much oil - and the fixative with it - are a challenge for all thickening motifs not to mention foaming. Yeesh!

  • Formula73

    Member
    December 20, 2023 at 3:21 pm

    I would try a different solubilizer that is also a surfactant like Aecosolv Olive & Aecosolv Sunflower from AE Chemie. For 2% fragrance, I would use Aecosolv at 5-6%, then add in the fragrance and mix over very low heat until transparent, then add to your cleanser. If they have a lot of restrictions such as no ethoxylates or PEGS, then for added thickening you will need to use Sepimax Zen from Seppic. To avoid aeration, add it to the batch and do not mix it until the next day. By the following day it would have been absorbed, so all you would need to do it mix slowly until all is incorporated. I do know the Zen is pricey, so I hope they have a good budget!

    Btw…that is way too much polymer. The rinse-off will be difficult. Thats why I never liked using it. If I did, I’d keep it at 8%, then add surfactant over it, which will neutralize it, thus eliminating the need for NaOH.. I’ve been doing this an extremely long time. Reach out anytime.

    • This reply was modified 4 months, 2 weeks ago by  Formula73.
    • This reply was modified 4 months, 2 weeks ago by  Formula73.
    • oldman20

      Member
      December 21, 2023 at 2:35 am

      i read from TDS’s Aecosolv: It solubilizes fragrance and a wide range of lipophilic ingredients to create clear formulations.

      So exactly Aecosolv is the solvent? What case is need it? when fragrance is too high?

  • chemicalmatt

    Member
    December 21, 2023 at 11:04 am

    None of those suggestions from @Formula73 will work here. Those Aecosolves are sodium lipid soaps and to add that much - especially in concert with the pricey Sepimax ZEN or any other acrylic (Sepimax being one of those) - will crash your viscosity down to the soup you are straining to avoid. The key problem here is viscosity build not so much fragrance solubilization, correct? Go with the W600 and add a nonionic such as PolySugaMulse D9 if fragrance clarity is a goal.

    • chem.ist

      Member
      December 21, 2023 at 12:09 pm

      correct! the issue is keeping the viscosity when that specific fragrance is added, all of the others dont have effect on the viscosity. What do you mean by fragrance clarity?

  • chemicalmatt

    Member
    December 21, 2023 at 12:50 pm

    The issue you are having was mistaken by contributors to be that of incorporating your fragrance into a clear body wash system without clouding or opacifying that system. That discussion referred to formulation clarity (opposite of opaque) not “fragrance clarity.” Your viscosity problem will be best solved using Synthalen W600 acrylic polymer which should not be affected by 2.00% fragrance oil, but as I said: your foam sure will be. Oils crash foam. Always.

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