Data Table: Materials
| Common Name | Natural Rubber | SBR | EPDM | Neoprene | CSM | Nitrile | Acrylic | Vamac® | Epichlorohydrin | Butyl | Silicone | HNBR | Viton® | Fluorosilicone | Kalrez® | Common Name |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Name | Polyisoprene | Styrene Butadiene Rubber | Ethylene Propylene Diene Monomer Rubber | Polychloroprene Rubber | Chlorosulphyl Polyethylene Rubber | Acrylonitrile Butadiene Rubber | Polyacryclic Rubber | Ethylene Acrylic Rubber | Epichlorohydrin Rubber | Polyisobutylene Rubber | Polysiloxane | Hydrogenated Nitrile Rubber | Fluorocarbon Rubber | Fluorosilicone Rubber | Perfluorocarbon Rubber | Chemical Name |
| Nomenclature | NR | SBR | EPDM | CR | CSM | NBR | ACM | AEM | ECO | IIR | Q | HNBR | FKM | FSi | FFKM | Nomenclature |
| Relative Cost | 1 | 1 | 1.5 | 1.5 | 1.5 | 1.5 | 3.5 | 4 | 4 | 4 | 11 | 20 | 30 | 40 | 1000 | Relative Cost |
| Hardness Range (IRHD) | 30-95 | 40-95 | 30-85 | 30-90 | 40-85 | 40-100 | 50-85 | 45-90 | 40-85 | 40-85 | 40-80 | 50-95 | 50-95 | 40-80 | 65-90 | Hardness Range (IRHD) |
| Colours | Full Range | Full Range | Limited Range | Full Range | Full Range | Limited Range | Black | Limited Range | Limited Range | Limited Range | Full Range | Limited Range | Limited Range | Limited Range | Limited Range | Colours |
| Heat Resistance Maximum Continuous Maximum Intermittent | 75°C 105°C | 85°C 115°C | 130°C 150°C | 95°C 125°C | 130°C 160°C | 100°C 130°C | 150°C 180°C | 150°C 180°C | 140°C 160°C | 120°C 135°C | 205°C 300°C | 150°C 180°C | 205°C 250°C | 180°C 200°C | 300°C 325°C | Heat Resistance Maximum Continuous Maximum Intermittent |
| Minimum Temperature | -60°C | -55°C | -50°C | -40°C | -25°C | -50°C to -5°C | -20°C | -40°C | -30°C | -50°C | -60°C(special grades -80°C) | -30°C | -40°C to 0°C | -60°C | 0°C (special grades -25°C) | Minimum Temperature |
History of elastomers
Rubber was first brought to Europe in 1493 from the Americas by Columbus, but it remained little more than a novelty for over 200 years. Interest eventually began to grow, and in 1770 Joseph Priestley noted its ability to rub out pencil marks, hence the name ‘rubber’.
This was followed by a rapid growth in technical developments and applications in the 19th century. Rubber began to be used as containers, flexible tubing, elastic bands and waterproofing, spurred by developments from Charles Macintosh and Thomas Hancock. Charles Goodyear’s discovery of vulcanisation using sulphur increased the natural strength and durability of rubber by cross-linking the molecules of the soft gum rubber into a tougher material.
Other technological advances included improved compounding techniques which enabled the use of anti-oxidants and accelerators, and the incorporation of carbon black to improve strength. This led to a vast increase in the number of applications, which included seals, belts, flooring, electrical insulators, springs, and pneumatic tyres.
As the number of applications increased, demand for the raw material grew rapidly. South America, particularly Brazil, was the prime source of natural rubber until the early 1900s. Then, British Asian colonies, using rubber trees from seeds smuggled out of the Amazon basin, began to compete with traditional sources.
The period between World Wars I and II witnessed the first development of a true synthetic substitute for natural rubber, ie, sodium polymerised butadiene, which was produced in Germany as Buna rubber and in the USSR as SK rubber. In the 1930s, Germany developed the emulsion copolymerisation of butadienestyrene (Buna S), whereas sodium polybutadiene continued as the principal general purpose synthetic rubber in the Soviet Union.
The advent of World War II highlighted the importance of rubber as a raw material. When the Axis powers gained control of nearly all the world’s supplies of natural rubber, this led to an urgent stepping up in the development of synthetic rubbers, particularly in the USA. Production of styrene-butadiene rubber (SBR), then called GR-S, began in a US government plant in 1942. Over the next three years, government-financed construction of 15 SBR plants brought annual production to more than 700,000 tonnes. A wide variety of synthetic rubbers have since been developed, and in the early 1960s production of natural rubber was surpassed by that of synthetic elastomers. By 1990, two-thirds of world rubber production consisted of synthetic varieties.
