Natural rubber. Description

Natural rubber is an amorphousa body that has the ability to crystallize. Natural material (untreated) - carbon is colorless or white. Natural rubber does not dissolve in alcohol, water, acetone and some other liquids. In aromatic and fatty hydrocarbons (ethers, benzene, gasoline and others), it swells and subsequently dissolves. As a result, colloidal solutions are formed, which are widely used in technical needs.

Natural rubber has a homogeneous molecular structure. The material possesses high physical and technological characteristics, it is easily subjected to processing on the corresponding equipment.

Natural rubber is distinguished by a highelasticity (elasticity). The material is capable of restoring its original form, when the forces that cause its deformation cease to affect it. It should be said that the elasticity persists in a fairly wide temperature range. However, prolonged storage provokes hardening of the material.

Natural rubber at minus one hundredninety-five degrees is transparent and hard, at temperatures from zero to ten degrees - opaque and brittle, at twenty - translucent, elastic and soft. When heated above 50 ° C, the material becomes ductile and sticky.

Its elasticity, it loses its temperaturemore than eighty degrees, at one hundred and twenty degrees it passes into a resinous liquid state, after hardening it is impossible to obtain the original product. When the temperature rises to two hundred to two hundred and fifty degrees, the natural rubber begins to decompose. As a result, a number of liquid and gaseous substances are formed.

Natural rubber is a good dielectric. In addition, the material has a low gas and water resistance.

Material is slowly oxidized by air oxygen. The process is faster under the influence of chemical oxidants.

In addition to all other properties, the rubber possessesplasticity. He is able to maintain the form that he acquired under the influence of external influences. Plasticity, which manifests itself during mechanical processing and heating, is considered one of the distinctive characteristics of the material. Due to the fact that the rubber has elastic and plastic properties, it is also called a plastic-elastic material.

Natural rubber, the formula of which is (C5H8) n,includes molecules containing a large number of double bonds. Material easily enters into chemical reactions with many substances. Increased reactivity is due to the unsaturated chemical nature of the material. The best interaction occurs in those solutions in which the rubber is represented by molecules of relatively large colloidal particles.

When stretching or cooling, a transition is observedmaterial into the crystalline state from amorphous (crystallization). This process takes place within a certain time, not so instantaneously. Crystals have a small size, an indefinite geometric shape, and their faces are indistinct.