Butyl alcohol

Butanol is the traditional name for one of the monohydric alcohols. To it the systematic name - 1-butanol, and also others - n-butanol (normal butanol) or butyl alcohol is applied. In the molecule of this primary alcohol there are four carbon atoms connected together, and the hydroxyl group replaces one hydrogen atom in the first atom of C. The chemical formula is C4H9OH, the rational is CH3 (CH2) 3OH, the empirical is C4H10O.

The molar mass of n-butanol is 74.1 g / mol. Under normal conditions, it is a liquid with a density of 0.81 g / cm³. The melting point of C4H9OH is minus 90.2 ° C, the boiling point is plus 117.4 ° C. The refractive index of a pure substance corresponds to 1.399. Self-ignition of 1-butanol at a temperature of plus 345 ° C, flare up at a temperature of plus 34 ° C.

Butyl alcohol is a linear hydrocarbon in which one hydrogen atom in the terminal C atom is replaced by a hydroxyl group. It has three isomers with systematic names:

• 2-methyl-1-propanol is a branched hydrocarbon with a methyl group at the second and a hydroxyl group at the first carbon atom;
• 2-butanol is a linear hydrocarbon with a hydroxyl group on the second carbon atom;
• 2-methyl-2-propanol is a branched hydrocarbon with methyl and hydroxyl groups at the second carbon atom.

Trivial names of the same substances in the same sequence: iso-butanol ( isobutyl alcohol ), sec-butanol and tert-butanol.

The molecules of butanol isomers differ in structure, therefore, all four substances with the general formula C4H9OH have different melting points, boiling points and other characteristics. For example, butyl and isobutyl alcohols have limited solubility, while the other two isomers completely mix with water. This is because in the structure of all alcohol (CnH2n + 1OH) there is a hydroxyl group that affects the polarity, the increase of which contributes to the increase of water solubility. At the same time, the increase in the number of carbon atoms in a molecule makes this process difficult. If such primary alcohols as methanol, ethanol and propanol completely mix with water, then n-butanol is moderately.

Tert-butyl alcohol (otherwise 2-methyl-2-propanol or t-butanol) is the simplest tertiary alcohol. It is a clear liquid (or a colorless solid). This alcohol is readily soluble in water, mixed with diethyl ether and ethanol. It is unique among the isomers of butanol, because it can harden at room temperature and melt at a temperature slightly above 25 ° C. Tert-butanol is a by-product in the production of isobutane from propylene oxide. In addition, it can be obtained by catalytic hydration from isobutylene.

Like many other alcohols, butyl alcohol is a harmful substance. But it showed a low level of toxicity in tests on laboratory animals, therefore it refers to sufficiently safe substances and is used in cosmetics. However, getting it through the skin into the human body can lead to depression of the central nervous system. The contact of alcohol in the eyes causes them to be strongly irritated, getting it on the skin is moderate. In most cases, butanol is rapidly metabolized into carbon dioxide. The main danger arises from prolonged exposure to fumes. Severe poisoning manifests itself by suppressing the central nervous system and can even cause death.

The term "technical alcohol" is most often applied to ethanol, but it can also be attributed to other alcohol. For example, in the case where butanol is considered as a component of motor fuel. It works more efficiently than ethanol, since the energy that is generated as a result of combustion of the same volume of fuel is higher in C4H9OH than in C2H5OH. Butanol can be used as an additive to diesel fuel, which helps to reduce the amount of soot in the exhaust gases.

Butyl alcohol is mainly used as a solvent or an auxiliary product for chemical synthesis, as well as fuel. As a solvent, it is used in chemical and textile industries. It is also a component of hydraulic and brake fluids or serves, in spite of its alcoholic aroma, as the basis for perfume.