who discovered the phenomenon of vulcanized rubber, not everyone knows.Although the person's name often mentioned in advertising messages.His name was Charles Nelson Goodyear, and today his name, "are" famous brand tires.Without his involvement, "Indian rubber" (rubber) may never have gained widespread use, t. To. She was just a gimmick, once brought from America.Over the years, numerous experiments conducted Charles blending rubber with various ingredients (from turpentine to toxic zinc oxide), while in 1839 did not reveal the composition of the substance is sulfur.
What is the process of vulcanization of rubber?From the viewpoint of chemistry - Compound flexible rubber molecules to form a three-dimensional spatial grid, wherein transverse chemical bonds are fairly rare.The latter property allows tires to remain the same highly flexible, there are some natural rubber from which it is made.
When vulcanizing rubber net can be obtained by heat or radiation, as well as the application of a special chemical agent.As a rule, the operation using special units like boilers, injection molding machines, presses, autoclaves, shaper-vulcanizer and heat transfer (from the hot steam to electrical heating).
temperature vulcanized raw rubber can be quite varied, depending on the usage of the final product.A classic range is from 130 to 200 degrees Celsius, although rubber coatings and adhesives sometimes cured at room temperature (at 20 degrees "cold vulcanization").Substances agents for this process are quite diverse.In most cases, the sulfur-vulcanization is conducted, that allows to receive the diene rubbers used in tire manufacture and rubber shoes.In addition, an important role is played by the so-called "boosters" (for the latter form of the process), it is preferably substituted sulfonamides and TIZOL.
hot vulcanization of rubber can be carried out in a very short period of time, if the process involved in chemical accelerators: dithiocarbamates or xanthates.In this case, the operation is fast at about 110-125 degrees.For the curing of certain adhesives and latex in the application of mixtures of sodium dimethyldithiocarbamate can be used, lower temperatures (20 to 100 degrees).
applied in the vulcanization of rubber auxiliary substances (oligoester acrylates, peroxides, phenol resin, etc..) Allow to obtain products with high heat resistance, solidity, improved dielectric properties.It is also an important role in the formation of a product (from the soles of boots to jewelry), antioxidants (play extend the life of rubber) and plasticizers, allowing to lower the viscosity of the material in the processing speed and "erase".
