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  1. #1

    Default Evaporation Rate / Molecular weights

    HI
    I am a newbie and my first post after lurking around and collecting my materials.

    As evaporation rate decides the TOP , Mid and Bottom notes, Is there a co relation of the same with the molecular weight of the materials?
    Also have artificial chemical creations been able to change the evaporation rate so that the notes can be changed, Why should vanilla be only in base and not in Top note? Why the Bergamot cannot be shifted to base. I am sure with all the modern technology this should be possible.

    Avninder Mutchall
    India

  2. #2

    Default Re: Evaporation Rate / Molecular weights

    Greetings Avninder,

    larger molecules tend to have greater intermolecular forces and therefore higher boiler points.

    Synthetics of higher molecular weight can sometimes possess similar odour characteristics to those of lower molecular weight, and vice versa. However, there isn't a set way to achieve this; sometimes they will smell similar, sometimes not.

    I'm not aware of a top note that smells much like vanillin. If you decrease the molecular weight by removing or decreasing the length of one of the groups, it tends to make it smell more smoky, spicy, or animalic. However, there are some materials that can help to increase the creaminess in the top, such as acetoin.

    I hope this helps.
    Last edited by Pears; 21st May 2019 at 12:55 AM.

  3. #3

    Default Re: Evaporation Rate / Molecular weights

    Thanks Pears, I will try Acetoin,
    So modern technology has not brought about changes.

    Sent from my Redmi Note 5 Pro using Tapatalk

  4. #4
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    Default Re: Evaporation Rate / Molecular weights

    Certain Technologies can be employed to place some topnotes in the bottom, but not so much vice versa.

  5. #5

    Default Re: Evaporation Rate / Molecular weights

    You can try converting the aldehydes to Schiff bases, or the alcohols to esters, for example.

    Yes, turning a base note into a similar top note is more difficult, partly because by decreasing the weight you're decreasing the complexity and therefore the number of possibilities. The chances of one of those possibilities matching what you're looking for therefore goes down.

  6. #6
    Dependent mattmeleg's Avatar
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    Default Re: Evaporation Rate / Molecular weights

    I can only reply to this "Why should vanilla be only in base and not in Top note? "

    there are a lot of natural and synthetic "fruity," smelling top notes...
    These are often used in women`s fragrances, "fruity-floral fragrances."
    Typically; fruity top notes; melon, strawberry, berries, etc...are the sweetest top notes available

    Materials which are THIN, BRIGHT and SWEET can be top notes.
    Materials which are ROUND, THICK and SWEET are usually base notes.

    Example of round, thick and sweet
    Vanilla = base note
    Benzoin + Peru Balsam + cocoa absolute = base notes
    Coumarin = basenote

    The above materials (in there natural form) are literally THICK, syrupy materials.
    Thick molecules that STICK to the skin, and take a long time to dry. Thick material, thick smell, long lasting.
    I want to help newbies, like me!
    Matt`s Youtube channel: we examine materials, make accords and simple perfumes and talk all things scent related.
    https://www.youtube.com/channel/UCpi...5IG9nbG20t-lIQ

  7. #7

    Default Re: Evaporation Rate / Molecular weights

    but, converting aldehydes to schiff bases does not necessarily mean turning a top note to a base note. most of the times the aroma impression of the initial aldehyde is quite different to the resulting schiff base.

  8. #8

    Default Re: Evaporation Rate / Molecular weights

    Quote Originally Posted by pavomi View Post
    but, converting aldehydes to schiff bases does not necessarily mean turning a top note to a base note. most of the times the aroma impression of the initial aldehyde is quite different to the resulting schiff base.
    Precisely, pavomi. That is why I said in post #2, "however, there isn't a set way to achieve this; sometimes they will smell similar, sometimes not".

  9. #9

    Default Re: Evaporation Rate / Molecular weights

    Quote Originally Posted by Pears View Post
    Precisely, pavomi. That is why I said in post #2, "however, there isn't a set way to achieve this; sometimes they will smell similar, sometimes not".
    sorry pears, i wasn't able to decipher your initial post in this details. didnt want to question your opinion. getting it now, and i totally agree

  10. #10
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    Default Re: Evaporation Rate / Molecular weights

    Quote Originally Posted by pavomi View Post
    but, converting aldehydes to schiff bases does not necessarily mean turning a top note to a base note. most of the times the aroma impression of the initial aldehyde is quite different to the resulting schiff base.
    The results depend upon many things... The choices of the starting materials is the key.

  11. #11

    Default Re: Evaporation Rate / Molecular weights

    Quote Originally Posted by pkiler View Post
    The results depend upon many things... The choices of the starting materials is the key.
    very true of course. but i disagree that creating schiff bases is a method to turn top notes to base notes, out of my experience.
    i handle the results as new aromas, that may smell similar, but wont have the spark of the aldehydes one starts with. in blends, schiff bases are quite useful to achieve an impression of extending top notes though.

    but maybe you have different experiences with creating schiff bases? would be very interesting to hear!

  12. #12

    Default Re: Evaporation Rate / Molecular weights

    There will always be some changes but the additional qualities may not be detrimental to the overall blend. If you were trying to replace one for the other entirely, then yes, that would be more difficult. There are ways to increase your chances of success but there is also an element of luck involved because it's impossible to calculate all of the variables. R&D therefore usually involves testing many different possibilities.

    Amutchall, you may also wish to try adding a little ethyl vanillin to the vanillin, as it will have greater impact than vanillin alone. A trace of vanilla cresol or 4-methyl guaicol can be added to enhance the realism and the smokiness.

  13. #13

    Default Re: Evaporation Rate / Molecular weights

    Thanks Pears, will use the Ethyl Vanillin and also the Cresol, will locate.




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