Acrolein (systematic name:
propenal) is the simplest
unsaturatedIn chemistry, saturation has five different meanings:#In physical chemistry, saturation is the point at which a solution of a substance can dissolve no more of that substance and additional amounts of it will appear as a precipitate...
aldehydeAn aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom bonded to a hydrogen atom and double-bonded to an oxygen atom , is called the aldehyde group...
. It is produced widely but is most often immediately reacted with other products due to its instability and toxicity. It has a piercing, disagreeable, acrid smell similar to that of burning fat.
Acrolein is prepared industrially by oxidation of propene. Efforts are under way to use
propanePropane is a three-carbon alkane, normally a gas, but compressible to a transportable liquid. It is derived from other petroleum products during oil or natural gas processing...
as feedstock for the synthesis; however, this is more difficult.
Several million tons of acrolein are produced each year.
When
glycerolGlycerol is an organic compound, also commonly called glycerin or glycerine. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. ...
is heated to 280 °C, it decomposes into acrolein.
Acrolein may also be produced on lab scale by the reaction of potassium bisulfate on glycerol (glycerine).
Acrolein is used in the preparation of
polyester resinPolyester resins are unsaturated resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Among other uses, it is the basic component of sheet moulding compound, bulk moulding compound and the toner of laser printers....
,
polyurethaneA polyurethane, IUPAC abbreviation PUR, but commonly abbreviated PU, is any polymer consisting of a chain of organic units joined by urethane links...
,
propylene glycolPropylene glycol, known also by the systematic name propane-1,2-diol, is an organic compound , with a faintly sweet taste, and is a colorless, nearly odorless, clear, viscous liquid that is hygroscopic and miscible with water, acetone, and chloroform...
,
acrylic acid,
acrylonitrileAcrylonitrile is the chemical compound with the formula CH2CHCN. This pungent-smelling colorless liquid often appears yellow due to impurities. It is an important monomer for the manufacture of useful plastics...
, and
glycerolGlycerol is an organic compound, also commonly called glycerin or glycerine. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. ...
.
Acrolein tends to polymerize when left at room temperature, leaving a gummy yellowish residue with a putrid odor.
Acrolein (systematic name:
propenal) is the simplest
unsaturatedIn chemistry, saturation has five different meanings:#In physical chemistry, saturation is the point at which a solution of a substance can dissolve no more of that substance and additional amounts of it will appear as a precipitate...
aldehydeAn aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom bonded to a hydrogen atom and double-bonded to an oxygen atom , is called the aldehyde group...
. It is produced widely but is most often immediately reacted with other products due to its instability and toxicity. It has a piercing, disagreeable, acrid smell similar to that of burning fat.
Synthesis
Acrolein is prepared industrially by oxidation of propene. Efforts are under way to use
propanePropane is a three-carbon alkane, normally a gas, but compressible to a transportable liquid. It is derived from other petroleum products during oil or natural gas processing...
as feedstock for the synthesis; however, this is more difficult.
Several million tons of acrolein are produced each year.
When
glycerolGlycerol is an organic compound, also commonly called glycerin or glycerine. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. ...
is heated to 280 °C, it decomposes into acrolein.
Acrolein may also be produced on lab scale by the reaction of potassium bisulfate on glycerol (glycerine).
Uses
Acrolein is used in the preparation of
polyester resinPolyester resins are unsaturated resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Among other uses, it is the basic component of sheet moulding compound, bulk moulding compound and the toner of laser printers....
,
polyurethaneA polyurethane, IUPAC abbreviation PUR, but commonly abbreviated PU, is any polymer consisting of a chain of organic units joined by urethane links...
,
propylene glycolPropylene glycol, known also by the systematic name propane-1,2-diol, is an organic compound , with a faintly sweet taste, and is a colorless, nearly odorless, clear, viscous liquid that is hygroscopic and miscible with water, acetone, and chloroform...
,
acrylic acid,
acrylonitrileAcrylonitrile is the chemical compound with the formula CH2CHCN. This pungent-smelling colorless liquid often appears yellow due to impurities. It is an important monomer for the manufacture of useful plastics...
, and
glycerolGlycerol is an organic compound, also commonly called glycerin or glycerine. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. ...
.
Acrolein tends to polymerize when left at room temperature, leaving a gummy yellowish residue with a putrid odor. It is also thought to be an intermediate in the
Skraup synthesisThe Skraup synthesis is a chemical reaction used to synthesize quinolines. It is named after the Czech chemist Zdenko Hans Skraup . In the archetypal Skraup, aniline is heated with sulfuric acid, glycerol, and an oxidizing agent, like nitrobenzene to yield quinoline.In this example, nitrobenzene...
of quinolines, but is rarely used as such due to its instability.
Acrolein is sometimes used as a fixative in preparation of biological specimens for electron microscopy. It is also used as a contact herbicide to control submersed and floating weeds, as well as algae, in irrigation canals.
Health risks
Acrolein is a severe
pulmonary irritantA pulmonary agent is a chemical weapon agent designed to impede a victim's ability to breathe. They operate by causing a build-up of fluids in the lungs which then leads to...
and
lachrymatory agentA lachrymatory agent or lachrymator is a chemical compound that stimulates the corneal nerves in the eyes to cause tearing, pain, and even temporary blindness. Common lachrymators include CS, CR, CN, bromoacetone, phenacyl bromide, and xylyl bromide...
. It was used as a chemical weapon during
World War IWorld War I , also known as the First World War, the Great War, and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente and the Triple Alliance...
. It is, however, not outlawed by the
Chemical Weapons ConventionThe Chemical Weapons Convention is an arms control agreement which outlaws the production, stockpiling and use of chemical weapons...
. Skin exposure to acrolein causes serious damage. Acrolein concentrations of 2 ppm are immediately harmful.
Acrolein is not a suspected
humanHumans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving member of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving...
carcinogenA carcinogen is any substance, radionuclide or radiation that is an agent directly involved in the promotion of cancer or in the increase of its propagation. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
; no studies have been conducted on the carcinogenic effects of acrolein on humans, but studies on rats have shown an increase in cancerous tumors from ingestion, but not from inhalation. In October 2006, researchers found connections between acrolein in the smoke from
tobacco cigarettes Tobacco smoking is the practice where tobacco is burned and the vapors either tasted or inhaled. The practice began as early as 5000–3000 BC. Many civilizations burnt incense during religious rituals, which was later adopted for pleasure or as a social tool. Tobacco was introduced to the old world...
and the risk of
lung cancerLung cancer is a disease of uncontrolled cell growth in tissues of the lung. This growth may lead to metastasis, which is the invasion of adjacent tissue and infiltration beyond the lungs. The vast majority of primary lung cancers are carcinomas of the lung, derived from epithelial cells...
. Furthermore, acrolein is a toxic metabolite of
cyclophosphamideCyclophosphamide , also known as cytophosphane, is a nitrogen mustard alkylating agent, from the oxazophorines group....
, a cytotoxic
chemotherapyChemotherapy, in its most general sense, is the treatment of disease by chemicals especially by killing micro-organisms or cancerous cells. In popular usage, it refers to antineoplastic drugs used to treat cancer or the combination of these drugs into a cytotoxic standardized treatment regimen...
agent, and results in
hemorrhagic cystitisHemorrhagic cystitis or Haemorrhagic cystitis is diffuse inflammation of the bladder leading to dysuria, hematuria, and hemorrhage. This is seen most often in female cancer patients as a complication of therapy, however it is can also be seen in children as a result of viral infection...
.
EPA method 603 is designed to measure acrolein in industrial and municipal
wastewaterWastewater is any water that has been adversely affected in quality by anthropogenic influence. It comprises liquid waste discharged by domestic residences, commercial properties, industry, and/or agriculture and can encompass a wide range of potential contaminants and concentrations...
streams.
Acrolein test
Acrolein test is a test for the presence of glycerin or
fatFats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. Chemically, fats are generally triesters of glycerol and fatty acids. Fats may be either solid or liquid at normal room temperature, depending on their structure and composition...
s. A sample is heated with potassium bisulfate, and acrolein is released if the test is positive. When a fat is heated strongly in the presence of a dehydrating agent such as KHSO
4, the glycerol portion of the molecule is dehydrated to form the unsaturated
aldehydeAn aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom bonded to a hydrogen atom and double-bonded to an oxygen atom , is called the aldehyde group...
, acrolein (CH
2=CH-CHO), which has the peculiar odor of burnt grease.