The vulcanization (or clearing out ) is the process of Pontage long molecules of rubber to make it plastic less but more elastic.

Technique

After Polymerization, in the presence of a system reticulating, the folded up macromolecules form a three-dimensional network without privileged direction pushing them to return in an initial state when the constraint is slackened.

The most visual representation to explain this phenomenon is the dish of spaghetti. The Polymère of rubber is a spaghetto. If there is a dish of spaghetti, one cannot seize only one spaghetto, the Force of van der Waals (electrostatic force of the type), that one finds within rubber ensure cohesion of it. However, if one takes time to draw gently on the spaghetto, one can extract only him.

Pareillement the natural rubber does not have solid consistency, it runs. If a pure rubber ball is made and that we pose it on a plane support, it will run to form a rubber puddle pool to the manner of a liquid. This experiment lasts a few hours. Thus, with the first access, rubber can appear elastic and besides the ball previously formed rebounds very well. The forces of Van der Waals ensure a sufficient cohesion to allow some elasticity.

To fix the phenomenon of cast iron and to add cohesion, one introduces Soufre. This last is mixed with rubber, the Cuisson allows a contribution of energy so that electronic connections (schematically, an exchange of electron) are carried out between sulfur and the Monomère S of rubber. That thus allows connection between two Polymère S and thus a durable cohesion of rubber. It appears thus that the proportioning of sulfur is essential, too much sulfur and rubber will not be elastic any more (too many monomers will be fixed units), not enough involving sulfur, for its part, less cohesion, and thus a weaker lifespan. Also let us note that the introduction of too much sulfur decreases, in the long term, the effect of the forces of Van der Waals, these last playing an extremely important part in the handling of the Automobile.

It is the heart of art and the science of the pneumatic manufacture of the S.

History

Charles Goodyear discovered it in January 1840 and its name comes from the Roman god Vulcan, a blacksmith.

Manufacture

The elastomer is the component main thing of a mixture which can comprise between 10 and 20 different ingredients. Some are necessary for vulcanization (Soufre, Péroxyde), others make it possible to accelerate the process of them. Some others protect (antioxidant,…), softened (Huile S, greases, Fatty-acids,…), or color (Oxyde of zinc, Lithopone,…). To facilitate the mixture of these ingredients, one uses a Solvant.

The products containing Carbonate of calcium or Sulface of barium improve its aspect. The black of Carbone increases resistance to the Abrasion.

Be-X-old: Вулканізацыя