Home Cosmetic Science Talk Formulating Precipitant after adding preservative in cleanser with aqua sf-2

  • Precipitant after adding preservative in cleanser with aqua sf-2

    Posted by hhsoap on August 4, 2024 at 11:40 am

    Hi,

    Weird problem with cleanser formula. Experimenting with aqua sf-2 for thickening (not suspending) in a high fragrance load cleanser formula.

    The same formula without the sf-2 is crystal clear, just thin.

    With the sf-2 formula, it is looking most excellent all the way until I added the preservative (pe 9010) and instantly a small amount of white precipitant forms which did not resolve after adding fragrance or heating (meant to be cold process, but tried heat to see if he precipitant would go away).

    I guess I could just try a different preservative. Any recommendations? The boss wants it paraben and formaldehyde donor free).

    Here is the formula in order:

    Water qs100

    Aqua sf-2 (Acrylates Crosspolymer-4) 4%

    DEF-61 (Sodium C14-16 Olefin Sulfonate, Cocamidopropyl Hydroxysultaine, Cocamide MIPA)(surfactant blend) 35%

    Citric acid qs pH 5.5 (~0.2%)

    Cola moist 200 (Hydroxypropyl Bis-Hydroxyethyldimonium Chloride)(conditioning) 2%

    Cola lipid c (Cocamidopropyl PG-Dimonium Chloride Phosphate) (conditioning) 1%

    Kelp extract (Macrocystis pyrifera (sea kelp) extract) 1%

    PE 9010 (phenoxyethanol and ehthylhexylglycerin) 0.5%

    Fragrance 1%

    Many thanks.

    chemicalmatt replied 2 months, 4 weeks ago 3 Members · 2 Replies
  • 2 Replies
  • Richard

    Member
    August 5, 2024 at 12:20 am

    Try removing the cationics. I expect not compatible with SF2

  • chemicalmatt

    Member
    August 20, 2024 at 1:16 pm

    That is weird. Nice knock-out work too there, my friend. Often pheoxyethanol crashes viscosity in surfactant systems but I’ve never known a ppt. to form. Must be somehow knocking out a crosslink in the SF-2, creating a less crystalline/less soluble sub chain? Anyhow, your pH is sufficiently low to accommodate an acid-based preservative , i.e. benzoate, sorbate, caprylhydroxamic, etc.. especially if you knock it down to pH4.8 - 5.2. Even better: do you have an objection to using Kathon (MIT)? Ideal for this formulation.

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