The etymology of the term elastomer refers us to two Greek words: elastós (which can be translated as “malleable” ) and méros ( “piece” or “part” ). An elastomer is a material that has high elasticity .
To understand what elastomers are, therefore, we must understand what elasticity is. This is the name given to the physical property of a solid body that allows it to return to its initial state once the influence of a force that deformed it has ceased. In other words: an element with high elasticity, when subjected to the action of a force, can stretch or deform without breaking and then, when the force ceases, recover its original shape.
Elastomers, in this framework, are artificial or natural materials that have a wide elasticity. These are usually polymers made up of monomers that are made up of oxygen, carbon, silicon or hydrogen.
Due to their molecular structure, elastomers can stretch up to 700% without suffering permanent deformation. This is because the polymer chains can modify their position to achieve efficient stress distribution. When the force is no longer applied, the covalent bond allows the elastomer to return to its original state.
There are different types of elastomers depending on their reaction to high temperatures and their chemical composition. If we take into account their thermal behavior, we find that there are two main types of elastomers:
-The so-called thermoplastic elastomers, which are identified because when the temperature rises they become very soft as well as moldable. This category includes olefinics, copolyamides or styrenics, among others.
-Thermo-stable elastomers, which when heated to a high temperature continue to remain solid. What's more, they don't alter their shape at all.
One of the best-known elastomers is natural rubber , which is obtained from the latex that is present in the sap of certain plants. There is also artificial rubber, produced by humans synthetically.
In addition to the aforementioned natural rubber, we must not overlook the existence of other very important elastomers, as would be the case, for example, of polyurethane, which is widely used in the textile field to shape materials such as lycra, or even neoprene. The latter, also known as chloropene, is used to manufacture alcohols, oils and fuels, among other things. Of course, it should not be overlooked that neoprene has experienced a significant boom in recent years because it is used to manufacture diving suits.
In the same way, there is also silicone, which has become a widely used elastomer in different sectors. Thus, it is used not only to create breast prostheses but also for baby bottle teats, to shape pacifiers...
Other interesting characteristics of elastomers are these that we present below:
-As a general rule, they are insoluble.
-They do not melt. What's more, before melting they have the ability to pass into the gaseous state.
-In the presence of certain solvents, what they do is swell.