Rubber products produced using natural rubber (aka India rubber) from rubber trees consists of organic compound isoprene polymers, plus water and other organics, which exhibits good mechanical properties. Natural rubber, however, has restricted thermal permanence and petroleum product compatibility.
Synthetic rubber, on the other hand, is a polymer, or elastomer, produced from synthesized petroleum products. Synthetic rubber products are produced using chloroprene, isoprene, or an isobutylene / isoprene combination. Typically, synthetic rubbers exhibit increased mechanical and chemical properties and endurances.
Viton is a synthetic, floronated hydrocarbon (fluorocarbon) rubber product produced and trademarked by DuPont Performance Elastomers (Viton refers to all types of DuPont fluoro-rubbers). Different kinds of fluoroelastomers possess different swell behaviors, and their processing / compression set resistance. The manufacturer produces the appropriate fluoroelastomer compound to meet the required application.
Viton has a maximum temperature resistance of 400°F (204°C) without sacrificing the life of the material. Fluoroelastomers tend to decompose at high temperatures. When exposed to fire, they can release hazardous hydrogen fluoride residue.
Viton does not retain its flexibility and acceptable performance for fixed applications in temperatures below -15°F (–26°C). In some applications Viton can perform in –40°F (–40°C) temps, and -5°F to 0°F (–15°C to –18°C) in certain dynamic situations.
Certain fluorocarbon compounds demonstrate enhanced resistance to temperature extremes, ozone, acids, fuels, steam, and water. Viton is additionally highly resistant to:
However, Viton does not resist acetones and ketones well. For example, gas permeability is low and similar to butyl rubber. Viton is also not compatible with glycol-based brake fluids, ammonia gas amines and alkalis, superheated steam, and fomic and acetic acids.
Viton rubber products have significant stretch without compromise. These elastomers are most commonly used as gasket material such as those that seal leaks, valves, pumps, etc.
Viton O-rings have been used in SCUBA diving gear by divers using Nitrox gases for some time because the Viton material is less likely to ignite the increased oxygen content in Nitrox. Decaying due to the increased oxygen content is also less.
Automotive and other transport fuel applications subjected to high (unstable / oxidizing) biodiesel concentrations recommend Viton-lined hoses and tubing. Viton and Buna are the most commonly-used elastomers used for (automotive) sealing. Viton O-rings provide similar functional characteristics and offer a higher temp and chemical resistance alternative to Buna-N seals in automobile engine timing units. While Viton O-ring performances may significantly vary, they are very compatible with hydrocarbons.
Finally, robust organic solvents, such as those composed of nitriles, also do not penetrate or damage highly-impermeable Viton/butyl gloves.