Acetic aldehyde (other names: acetaldehyde, methyl formaldehyde, ethanal) is an organic compound belonging to the class of aldehydes. This substance is important for humans, it is found in coffee, bread, ripe fruits and vegetables. It is synthesized by plants. It is found in nature and is produced in large quantities by humans. Formula of Acetic Aldehyde: CH3-CHO.
Physical properties
1. Acetic aldehyde is a colorless liquid with a pungent unpleasant odor.
2. It is well soluble in ether, alcohol and water.
3. The molar mass is 44.05 gram / mol.
4. The density is 0.7 grams / centimeterยณ.
Thermal properties
1. The melting point is -123 degrees.
2. The boiling point is 20 degrees.
3. The ignition temperature is -39 degrees.
4. The autoignition temperature is 185 degrees.
Preparation of Acetic Aldehyde
1. The main way to obtain this substance is the oxidation of ethylene (the so-called Wacker process). This reaction looks like this:
2CH2 = C2H4 (ethylene) + O2 (oxygen) = 2CH3CHO (methyl formaldehyde)
2. Acetic aldehyde can also be obtained by hydration of acetylene in the presence of mercury salts (the so-called Kucherov reaction). In this case, phenol is obtained, which is then isomerized to the aldehyde.
3. The following method was popular until the above process. It was carried out by oxidation or dehydrogenation of ethyl alcohol on a silver or copper catalyst.
The use of acetic aldehyde
- What substances do you need acetic aldehyde for? Acetic acid, butadiene, aldehyde polymers and some other organic substances.
- Used as a precursor (a substance that is involved in the reaction leading to the creation of the target substance) to acetic acid. However, they soon stopped using the substance we are considering. This happened because acetic acid is easier and cheaper to produce from metal using the processes of Cativa and Monsanto.
- Methyl formaldehyde is an important precursor to pentaerythrol, pyridine derivatives and crotonaldehyde.
- Obtaining resins due to the fact that urea and acetic aldehyde have the ability to condense.
- Obtaining ethylidene diacetate, from which polyvinyl acetate (vinyl acetate) monomer is subsequently produced.
Tobacco dependence and acetic aldehyde
This substance is a significant part of tobacco smoke. Recently, a demonstration was conducted in which it was shown that the synergistic relationship of acetic acid with nicotine increases the manifestation of dependence (especially in individuals under thirty years of age).
Alzheimer's Disease and Acetic Aldehyde
Those people who do not have a genetic factor for the conversion of methyl formaldehyde to acetic acid have a high risk of predisposition to a disease such as senile dementia (or Alzheimer's disease), which usually occurs in old age.
Alcohol and methyl formaldehyde
Presumably, the substance we are considering is a carcinogen for humans, since today there is evidence of carcinogenicity of acetic aldehyde in various animal experiments. In addition, methyl formaldehyde damages DNA, thereby causing the development of the muscular system disproportionate to body weight, which is associated with impaired protein metabolism in the body. A study of 800 alcoholics was conducted, as a result of which scientists concluded that people exposed to acetic aldehyde have a defect in the gene of one enzyme - alcohol dehydrogenase. For this reason, such patients are more at risk of developing cancer of the kidneys and upper liver.
Security
This substance is toxic. It is an air pollutant from smoking or from exhausts in traffic jams.