Acetaldehyde (other names: acetaldehyde, metilformaldegid, ethanal) - is an organic compound belonging to the class of aldehydes.This substance is important to the person, it is found in coffee, bread, ripe fruits and vegetables.Synthesized by plants.It occurs in nature and is produced in large quantities by man.Acetaldehyde formula: CH3-CHO.
physical properties
1. Acetaldehyde - a colorless liquid with a sharp odor.
2. It is readily soluble in ether, alcohol and water.
3. The molar mass of 44.05 grams / mole.
4. The density is 0.7 g / santimetr³.
Thermal properties
1. The melting point is -123 degrees.
2. Boiling point is 20 degrees.
3. The ignition temperature is -39 degrees.
4. Auto-ignition temperature is 185 degrees.
Getting acetaldehyde
1. The primary method of producing this substance is the oxidation of ethylene (the so-called process Vaquera).It looks like this reaction: 2CH2 =
C2H4 (ethylene) + O2 (oxygen) = 2CH3CHO (metilformaldegid)
2. Also, acetaldehyde can be produced by the hydration of the acetylene in the presence of mercury salts (so-called reaction Kucherova).This gives a phenol which is then isomerized to the aldehyde.
3. The following method was popular before the advent of the above-described process.It is performed by oxidation or dehydrogenation of ethyl alcohol in a silver or copper catalyst.
Application acetaldehyde
- For which substances need acetaldehyde?Acetic acid, butadiene, aldehyde polymers, and some other organic substances.
- used as a precursor (a substance that participates in the reaction leading to creation of a target substance) in acetic acid.However, since we are considering the substance apply soon ceased.This occurred for the reason that acetic acid is simpler and cheaper to produce by means of METALON Kativa and Monsanto processes.
- Metilformaldegid - an important precursor to pentaerythritol, pyridine derivatives and krotonaldegidu.
- Preparation of the resins due to the fact that urea and acetaldehyde have the ability to condense.
- Preparation ethylidene diacetate, which later produce polyvinyl monomer (vinyl acetate).
tobacco dependence and acetaldehyde
This substance - a significant portion of tobacco smoke.Recently there was a demonstration on which it was shown that the synergistic relationship of acetic acid increases expression of nicotine dependence (especially in those thirty years).
Alzheimer's disease and acetaldehyde
Those people who do not have a genetic factor metilformaldegida conversion into acetic acid, have a high risk of predisposition to disease such as senile dementia (or Alzheimer's disease), which usually occurs in old age.
Alcohol and metilformaldegid
Presumably we are considering the substance is a human carcinogen, as of today there is evidence of carcinogenicity of acetaldehyde in various experiments on animals.In addition, metilformaldegid damages DNA, thereby causing a disproportionate body weight development of the muscular system, which is related to the metabolism of protein in the body.A study was conducted of 800 alcoholics, as a result of which scientists have found that people exposed to acetaldehyde, there is a defect in the gene for one enzyme - alcohol dehydrogenase.For this reason, such patients are at greater risk of developing cancer of the kidneys and the upper part of the liver.
Security
This material is toxic.Atmosphere is a pollutant when smoking or exhaust in traffic jams.
