Butanol is the traditional name for one of the monohydric alcohols. The systematic name 1-butanol is applied to it, as well as others - n-butanol (normal butanol) or butyl alcohol. The molecule of this primary alcohol has four carbon atoms interconnected, and the hydroxyl group replaces one hydrogen atom at the first atom C. The chemical formula is C4H9OH, the rational is CH3 (CH2) 3OH, and the empirical is C4H10O.
The molar mass of n-butanol is 74.1 g / mol. In normal condition, it is a liquid with a density of 0.81 g / cm³. The melting point of C4H9OH is minus 90.2 ° C, and the boiling point is plus 117.4 ° C. The refractive index of a pure substance is 1.399. 1-butanol spontaneously ignites at a temperature of plus 345 ° C; it can flare up at a temperature of plus 34 ° C.
Butyl alcohol is a linear hydrocarbon in which one hydrogen atom at the extreme 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 - a linear hydrocarbon with a hydroxyl group at the second carbon atom;
- 2-methyl-2-propanol is a branched hydrocarbon with methyl and hydroxyl groups at the second carbon atom.
The trivial names of the same substances are 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, boiling, and other characteristics. For example, butyl and isobutyl alcohols have limited solubility, while the other two isomers are completely miscible with water. This is because in the structure of all alcohols (CnH2n + 1OH) there is a hydroxyl group that affects the polarity, an increase in which increases the solubility in water. At the same time, an increase in the number of carbon atoms in the molecule complicates this process. If primary alcohols such as methanol, ethanol and propanol are completely mixed with water, then n-butanol is mild.
Tert-butyl alcohol (aka 2-methyl-2-propanol or tert-butanol) is the simplest tertiary alcohol. It is a clear liquid (or a colorless solid). This alcohol is highly soluble in water, mixed with diethyl ether and ethanol. It is unique among butanol isomers because it can solidify at room temperature and melt at a temperature slightly above 25 ° C. Tert-butanol is a byproduct of 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 he showed a low level of toxicity when tested in laboratory animals, therefore, refers to a fairly safe substance and is used in cosmetics. However, its penetration through the skin into the human body can lead to depression of the central nervous system. The ingress of alcohol into the eyes causes severe irritation; contact with the skin is moderate. In most cases, butanol is rapidly metabolized to carbon dioxide. The main danger arises from prolonged exposure to vapors. Severe poisoning is manifested by suppression of 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 with greater efficiency than ethanol, since the energy that is generated as a result of the combustion of the same amount of fuel is higher for C4H9OH than for C2H5OH. Butanol can be used as an additive to diesel fuel, which helps to reduce the soot content in exhaust gases.
Butyl alcohol is mainly used as a solvent or 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, despite its alcoholic aroma, serves as the basis for perfume.