Amyl Acetate

views updated

Amyl Acetate

OVERVIEW

Amyl acetate (A-mil AS-uh-tate) is a colorless liquid with a distinctive banana-like flavor and odor. Three major isomers of amyl acetate exist: normal (n-amyl), secondary (secamyl), and isoamyl (3-methyl-1-butyl) acetate. Isomers are two or more forms of a chemical compound with the same molecular formula, but different structural formulas and different chemical and physical properties. As an example, the boiling points of the three isomers of amyl acetate are 149.2°C (300.6°F), 142.0°C (287.6°F), and 140.0°C (284.0°F), respectively. Although the amyl acetates are probably best known as flavoring agents because of their distinctive banana-like flavor, they all have a number of interesting industrial applications also.

KEY FACTS

OTHER NAMES:

Pentyl acetate; acetic acid, amyl ester

FORMULA:

CH₃COOC₅H₁₁

ELEMENTS:

Carbon, hydrogen, oxygen

COMPOUND TYPE:

Ester (organic)

STATE:

Liquid

MOLECULAR WEIGHT:

130.18 g/mol

MELTING POINT:

−70.8°C (−95.4°F)

BOILING POINT:

149.2°C (300.6°F)

SOLUBILITY:

Slightly soluble in water; soluble in alcohol, ether, and most organic solvents

HOW IT IS MADE

The amyl acetates are made industrially in essentially the same way they are made in a high school or college chemistry laboratory. Acetic acid (HC₂H₃O₂) is added to amyl alcohol (C₅H₁₁OH) with a small amount of concentrated sulfuric acid (H₂SO₄) as a catalyst. The specific amyl acetate produced depends on the specific amyl alcohol used in the reaction. The product is separated from the reaction mixture by boiling the liquid mixture.

COMMON USES AND POTENTIAL HAZARDS

Amyl acetate is used as a flavoring agent in the United States and several other countries. It is often blended with other esters to produce flavors that are more fruity and rounded. The compound is also used to flavor products such as chewing gum.

Some applications of amyl acetate depend on its distinctive banana-like odor. The compound may be used, for example, to cover up the unpleasant odors present in certain products, such as shoe polish. Amyl acetate is also used as a warning odor in devices through which gases flow, such as respirators. A warning odor is a distinctive smell that allows users to be aware that a leak exists in a product carrying a gas that has no odor of its own.

Among the many industrial applications of amyl acetate are the following:

As a solvent for paints and lacquers;
As an ingredient in fingernail polishes;
In the production of penicillin; and
In the manufacture of photographic film, printed and dyed fabrics, and phosphors used in fluorescent lamps.

Amyl acetate is thought to pose a moderate to low health risk. It may cause respiratory problems if inhaled or damage to the skin and eyes if spilled on the body. The most serious safety risk it poses is its flammability. It catches fire easily and burns rapidly, with a moderate risk of exploding under certain circumstances.

Interesting Facts

Amyl acetate is the primary component of banana oil and pear oil.

Words to Know

CATALYST: A material that increases the rate of a chemical reaction without undergoing any change in its own chemical structure
ESTER: An organic compound formed in the reaction between an organic acid and an alcohol.
ISOMER: Two or more forms of a chemical compounds with the same molecular formula, but different structural formulas and different chemical and physical properties
PHOSPHOR: A chemical that gives off light when exposed to an electrical current.

FOR FURTHER INFORMATION

"Amyl Acetate." CAMEO: Conservation and Art Material Encyclopedia Online. http://www.mfa.org/_cameo/frontend/material_description.asp?name=amyl+acetate&language;=1 (accessed on September 21, 2005).

"n-amyl acetate." CHEMINFO. http://intox.org/databank/documents/chemical/amylacet/cie455.htm (accessed on September 20, 2005).

"n-amyl acetate." New Jersey Department of Health and Senior Services. http://www.state.nj.us/health/eoh/rtkweb/1321.pdf (accessed on September 21, 2005).

"sec-amyl acetate." CHEMINFO. http://intox.org/databank/documents/chemical/amylacet/cie468.htm (accessed on September 20, 2005).

"sec-amyl acetate." New Jersey Department of Health and Senior Services. http://www.state.nj.us/health/eoh/rtkweb/1643.pdf (accessed on September 21, 2005).

Chemical Compounds