Home Cosmetic Science Talk Formulating Emogreen L15 volatility

  • pharma

    Member
    October 24, 2020 at 5:54 pm
    Emulgreen L15’s INCI is C15-19 alkanes meaning that some molecules in there does evaporate but rather slowly whilst others nearly don’t.
    Pentadecane (C15) is liquid at RT and has a high vapour pressure which, like essential oils, lets them evaporate well below its boiling temperature.
    The other end of the mixtures spectrum is nonadecane (C19) which is solid at RT and has a very low vapour pressure, it does not really evaporate but feels dry (because it’s solid).
    If you’re looking for faster drying and full evaporation, go with undecane, dodecane, and/or tridecane (C11-13) which evaporate fast and dry quickly or isododecane which has about the same vapour pressure as ethanol and takes longer to fully dissipate. Notably, C4 and C5 have lower vapour pressure but still evaporate.
    What all these molecules have in common and what seems contradictory to volatility is a high boiling point well above 200°C (if memory serves me right). The reason which greatly contributes to their good volatility is small molecular weights and low intermolecular interactions. Meaning, the lower the number in their INCI name, the faster they evaporate.
  • natiyo123

    Member
    October 24, 2020 at 10:27 pm

    Im guessing lower viscosity grades also mean, a higher % of lower molecular weights=higher evaporation rates?

    Thank you for your answer

  • mattthechemist

    Member
    October 24, 2020 at 11:06 pm

    I have had great success with the undecane/tridecane combo (Cetiol Ultimate) that Pharma mentioned, as a direct replacement for volatile silicones

  • graillotion

    Member
    October 24, 2020 at 11:42 pm

    Pharma said:

    Emulgreen L15’s INCI is C15-19 alkanes meaning that some molecules in there does evaporate but rather slowly whilst others nearly don’t.
    Pentadecane (C15) is liquid at RT and has a high vapour pressure which, like essential oils, lets them evaporate well below its boiling temperature.
    The other end of the mixtures spectrum is nonadecane (C19) which is solid at RT and has a very low vapour pressure, it does not really evaporate but feels dry (because it’s solid).
    If you’re looking for faster drying and full evaporation, go with undecane, dodecane, and/or tridecane (C11-13) which evaporate fast and dry quickly or isododecane which has about the same vapour pressure as ethanol and takes longer to fully dissipate. Notably, C4 and C5 have lower vapour pressure but still evaporate.
    What all these molecules have in common and what seems contradictory to volatility is a high boiling point well above 200°C (if memory serves me right). The reason which greatly contributes to their good volatility is small molecular weights and low intermolecular interactions. Meaning, the lower the number in their INCI name, the faster they evaporate.

    I have been fascinated with the ‘canes’….but have been unable to work with them.  Due to living on a rock in the middle of the Pacific, everything must be air freighted in….and so anything with a low flash point, I can not acquire (without moving mountains). 

    Does anything have these properties, with a higher flash point (I know….counter intuitive), that I could work with it?

    Is there a combo like Cetiol Ultimate, that some sort of synergy magical raises the flashpoint?  :p 

  • pharma

    Member
    October 25, 2020 at 8:05 am
    @Graillotion You can’t raise the flash point by mortal means but have to use black magic. Alas, that one is not approved for cosmetics ;( .
    @@natiyo123 Partially correct. Good enough for a cosmetic everyday situation.
  • natiyo123

    Member
    October 30, 2020 at 7:42 pm

    I have had great success with the undecane/tridecane combo (Cetiol Ultimate) that Pharma mentioned, as a direct replacement for volatile silicones

    Sounds like an ideal option, but I cant seem to find it in México where Im located. Fortunately, I found an Inolex distrib.  Im going to try lexfeel wow (C13-C15 alkanes) 

    Thanks everyone!
     

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