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Mineral oil emulsifier
Hello!
I’m working on a formulation, but it keeps separating at 30 deg C after about 48 hours. I have tried 3 different HLB surfactants (sorbitan monooleate,
C11-15 Pareth-5, Octoxynol-9). The best results were with a blend of sorbitan monooleate and C11-15 Pareth-5. The base formulation is simple:
~80% water
~15% mineral oil
~2-4% surfactant
~1-3% thickening agent
~0.1% methylisothiazolinone (preservative)
~1% fragrance (blend of essential oils in a DPG carrier)I’m also struggling with the thickener. I have tested the following:
- acrylates octylacrylamide copolymer
- ethyl cellulose
- Hydroxypropyl Methylcellulose
- guar gumI always end up with some white solids that settle to the bottom after a couple of days. I have tried predispersing in oil, ambient temperature, heating to 80 deg C, high shear mixing. I haven’t tried adjusting the pH beforehand… that was going to be my next test. I’m also thinking about testing styrene acrylates copolymer.
I’m probably making a bunch of rookie mistakes… so I apologize if I’m asking dumb questions. Any guidance would be greatly appreciated.
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3 Replies
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@rjd1234 Sorbitan Oleate, (which I think is the same as Sortbitan Monooleate) has HLB of 4.3. Mineral oil has HLB of 10.
4% of Sorbitan Oleate is not enough for that much of oil. Change an emulsifier. Are you willing to use PEGs? -
have u tried Cetosteryl Alcohol?What about pH? -
I would say Glyceryl Stearate/PEG-100 Stearate blend at 4% (HLB is 11.5)
Add 3% of Cetearyl Alcohol and 4% of Cetyl Alcohol (thickeners, emollients). Cetyl Alcohol, Cetearyl Alcohol and Mineral oil will be your oil phase with HLB of 11.7, so Glyceryl Stearate/PEG-100 Stearate should emulsify it. Please note the HLB is just a starting poing. It doesn’t mean that perfect HLB match ensures perfect emulsion, but the combination I mentions above usually works.
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