Who discovered the phenomenon of rubber vulcanization, and what is it?

Who discovered the phenomenon of vulcanization of rubber, knows noteach. Although the name of this person is often mentioned in advertising messages. His name was Charles Nelson Goodyear, and today his name is "worn" the tires of a famous brand. Without his participation, "Indian rubber" (rubber), perhaps, would never have been widely used, because it was just a curiosity brought back from America. For many years, Charles has carried out numerous experiments to mix rubber with various components (from turpentine to toxic zinc oxide), until in 1839 he discovered the composition of this substance with sulfur.

What is the process of vulcanizationrubber? From the point of view of chemistry, this is the combination of flexible rubber molecules in a three-dimensional grid of a spatial form, with the transverse chemical bonds being quite rare. The last property allows the rubber to remain as highly elastic as there is a natural rubber from which it is made.

With the vulcanization of rubber mesh can be obtained underexposure to high temperature or radiation, and when using a special chemical agent. As a rule, special units such as boilers, injection molding machines, presses, autoclaves, mold-vulcanizers and coolants (from hot steam to electric heating) are used for the operation.

The vulcanization temperature of the raw rubber may bequite diverse, depending on how the final product is used. The range is from 130 to 200 degrees Celsius, although rubber coatings and sealants are sometimes vulcanized at room temperature (at 20 degrees, "cold vulcanization"). Substances-agents for this process are quite diverse. Most often, sulfur vulcanization is carried out, which allows to obtain diene rubbers used in the production of tires and rubber shoes. In addition, the so-called "accelerators" (for the latter type of process) play an important role, they are predominantly sulfonamides and substituted tizols.

Hot vulcanization of rubber can be carried outin a very short period of time, if accelerators are involved in the chemical process: dithiocarbamates or xanthates. In this case, the operation passes quickly at a temperature of about 110-125 degrees. To vulcanize certain adhesives and latex mixtures with sodium dimethyldithiocarbamate, lower temperatures (from 20 to 100 degrees Celsius) can be used.

Used in the vulcanization of rubberadditional substances (oligoether acrylates, peroxides, phenol-formaldehyde resins, etc.) make it possible to obtain products with high heat resistance, monolithicity, and improved dielectric properties. Antioxidants (increase the service life of rubber) and plasticizers, which allow to lower the viscosity of the substance during processing and the speed of "erasing", play an important role in the formation of this or that product (from the sole for boots to costume jewelry).