They are characterized by allowing enormous elastic deformations, of the order of 1000 %. This quality is achieved after vulcanization (addition of sulfur to the mass, followed by a rise in temperature up to 145 °C and a pressure of about 5 atmospheres).
Oxygen, heat and sunlight slowly act on elastomers, reducing the elasticity of the material.
Natural Elastomer:
- It is obtained from a milky juice, called latex, exuded by certain tropical trees when small cuts are made in their trunks. The most important of these trees is called hevea.
- Nowadays, it has been practically replaced by synthetic rubber, since it is cheaper and has better qualities.
- Its applications are usually restricted to mattresses and pillows.
Synthetic Elastomer:
Neoprene
- Formed by a chloroprene polymer.
- It is non-combustible and does not deteriorate easily. It is used as insulation for
cables and clothing for divers and firefighters.
Silicones
- They are silicon based (inorganic products). They are very resistant to external agents.
Synthetic Rubber
- They are highly resistant to heat, abrasion and aging. The most important are: SBR (patented in Germany in 1929 and distributed under the trade name Buna S) and GR-S (from Government Rubber-Styrene, created in Germany in 1942, at the height of World War II, to compensate for the shortage of rubber).
- 80% of synthetic rubber is used in the manufacture of tires.