What is isoprene? The general formula of this compound corresponds to the homologous series of diene hydrocarbons and has the composition CnH2n-2. We will analyze some methods of obtaining this chemical compound, and also find out the main areas of its application.
Brief description of physical properties
We list the main physical properties of isoprene. This diene hydrocarbon is toxic, has little solubility in water. High concentrations of this drug have a narcotic effect. The maximum permissible concentration, harmless to humans, is 40 mg / cm 3 . With an increase in this indicator, 2-methylbutadiene-1.3 negatively affects the human psyche. Under ordinary conditions, this substance is a colorless volatile liquid having a low boiling point.
Chemical Features
What is characterized by the structural formula of isoprene? The composition of this organic compound contains two double bonds. It is they that characterize the main chemical interactions of this representative of diene compounds with other organic and inorganic substances. Isoprene is quite easily oxidized in atmospheric oxygen, while the reaction products are peroxides.
Polymerization
Does isoprene enter polymerization? The general formula for the class to which this hydrocarbon belongs is CnH2n-2. Like other representatives of the homologous series of butadiene-1,3, isoprene is capable of forming a high molecular weight compound.
During the polymerization process, the formation of cis and trans isomers of polyisoprene, which are analogues of natural rubber.
Getting natural rubber
What is the production of isoprene? The reactions that occur in this case are associated with the conversion of isoprene monomer to polymer - polyisoprene. To isolate natural rubber having a similar structure with 2-methylbutadiene-1,3, milky sap of tropical trees is used.
The resulting juice is subjected to vulcanization, which consists in the processing of sulfur chloride. In this chemical reaction, rubber absorbs a certain amount of sulfur, acquiring plasticity, elasticity. The polymerization product is resistant to temperature extremes, aggressive chemicals. The structural formula of isoprene explains the features of the vulcanization process.
If sulfur is taken from 25 to 40 percent for a given chemical interaction, ebonite can be obtained. This substance has high strength, it is used as an excellent insulating material. The structural formula of isoprene, which entered into interaction with sulfur, does not contain double bonds. It is the structure of the product that explains its mechanical strength.
All polymers used in the manufacture of airplane, automobile, bicycle chambers and tires are considered polyisoprene rubbers.
What else can the structural formula of isoprene tell us? It is capable of double-bonding reactions with molecules of halogen-hydrogen, halogen, hydrogen, water. These reactions prove that isoprene belongs to the class of unsaturated hydrocarbons.
Industrial production methods
There are several methods for the industrial production of isoprene. For example, in the reaction of acetylene with acetone, the reaction involves the formation of an intermediate product of methibutinol. After its hydrogenation, subsequent dehydration, isoprene is formed. It is also possible to obtain 2-methylbutadiene-1,3 from propylene. When selecting catalysts, methane can be obtained as an additional substance.
Isoprene Use
The bulk of the isoprene produced is used to synthesize isoprene rubber. In its physical and chemical characteristics, it is almost identical to natural material. Among the areas of application of the finished macromolecular compound, we call the manufacture of car tires.
In addition to the cis isomer, among the polymerization products, there is also a trans isomer having gutta-percha characteristics. It does not have much industrial use. This polymer substance is used to create golf balls, as well as for the production of insulation of electrical wires. Among the important industries for the use of isoprene, one can single out the synthesis of polymeric materials of the type styrene-isoprene-styrene. Products of this kind are used as thermoplastic materials and pressure sensitive adhesives.
Isoprene is necessary for the synthesis of butyl rubber, its quantitative content in it reaches up to three percent.
Since the end of the last century, the industrial production of terpenes from the initial mixture of isoprene, acetylene, and acetone has begun in the United States of America. The technology on which this method was based suggested a two-stage synthesis.