A fixative is used to equalize the
vapor pressure
Vapor pressure (or vapour pressure in English-speaking countries other than the US; see spelling differences) or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed pha ...
s, and thus the
volatilities, of the raw materials in a
perfume
Perfume (, ; french: parfum) is a mixture of fragrant essential oils or aroma compounds (fragrances), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agreeable scent ...
oil, as well as to increase the tenacity.
Fixatives can be resinoids (
benzoin,
labdanum
Labdanum, also called ladanum, ladan, or ladanon, is a sticky brown resin obtained from the shrubs ''Cistus ladanifer'' (western Mediterranean) and '' Cistus creticus'' (eastern Mediterranean), species of rockrose. It was historically used in he ...
,
myrrh
Myrrh (; from Semitic, but see '' § Etymology'') is a gum-resin extracted from a number of small, thorny tree species of the genus '' Commiphora''. Myrrh resin has been used throughout history as a perfume, incense and medicine. Myrrh m ...
,
olibanum,
storax,
tolu balsam) or the molecules
ambroxide,
civetone and
muscone
Muscone is an organic compound that is the primary contributor to the odor of musk.
The chemical structure of muscone was first elucidated by Leopold Ružička. It consists of a 15-membered ring ketone with one methyl substituent in the 3-positi ...
, which were originally obtained from animals, but can and are now mostly synthesized because it is more economical, more consistent and more ethical (animals were either killed or are kept in captivity to collect the secretions from their perineal glands). Synthetic fixatives include substances of low volatility (
diphenylmethane,
dipropylene glycol
Dipropylene glycol is a mixture of three isomeric chemical compounds, 4-oxa-2,6-heptandiol, 2-(2-hydroxy-propoxy)-propan-1-ol, and 2-(2-hydroxy-1-methyl-ethoxy)-propan-1-ol. It is a colorless, nearly odorless liquid with a high boiling point and ...
(DPG),
cyclopentadecanolide,
ambroxide,
benzyl salicylate) and virtually odorless
solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...
s with very low vapor pressures (
benzyl benzoate
Benzyl benzoate is an organic compound which is used as a medication and insect repellent. As a medication it is used to treat scabies and lice. For scabies either permethrin or malathion is typically preferred. It is applied to the skin as a ...
,
diethyl phthalate
Diethyl phthalate (DEP) is a phthalate ester. It occurs as a colourless liquid without significant odour but has a bitter, disagreeable taste. It is more dense than water and insoluble in water; hence, it sinks in water.
Synthesis and applicatio ...
,
triethyl citrate
Triethyl citrate is an ester of citric acid. It is a colorless, odorless liquid used as a food additive ( E number E1505) to stabilize foams, especially as whipping aid for egg white. It is also used in pharmaceutical coatings and plastics.
...
).
References
Perfume ingredients
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