Below are brief summaries of the properties of eight of the most versatile polymers. This information is not
all-inclusive; however, a majority of sealing, gasketing and weather stripping needs can be met by using these
popular materials.
Silicone
Silicone (Polysiloxane) features excellent resistance to ozone, sunlight and oxidation and is very color stable.
It also maintains excellent flexibility at low temperatures, has outstanding resistance to high heat, a low
compression set and is a very good electrical insulator; however, it is not recommended for applications that
require abrasion resistance, tear and cut growth resistance and high tensile strength, nor is it recommended for
resistance to oil, gasoline, solvents, alkalis, and acids.
EPDM
EPDM (Ethylene-Propyline-Diene-Monomer) is well known for its excellent ozone, weathering and aging resistance.
It also has excellent water and stream resistance, maintains its flexibility at low temperatures, features
excellent resistance to alkalis, acids and oxygenated solvents, and is very color stable. It is not recommended
for resistance to oil, gasoline and hydrocarbon solvents. EPDM is found in a wide range of applications and is
excellent for outdoor use.
Neoprene
Neoprene (Polychloroprene) has moderate resistance to oils and gasoline. It features good flame resistance,
weathers well and has very good resistance to abrasion, flex cracking, alkalis and acids. However, expect poor
resistance to aromatic and oxygenated solvents and limited flexibility at low temperatures. Neoprene is generally
considered an excellent all-purpose elastomer with a solid balance of properties and few limitations.
Nitrile
Nitrile (Acrylonitrile-butadiene) has very good oil and abrasion resistance to alkalis and acids increases as the
nitrile content of the compound increases. Nitrile must be specially compounded for resistance to ozone, sunlight
and natural aging. It has poor resistance to oxygenated solvents. Nitrile is superior to neoprene in oil and
solvent resistance but is not recommended for applications where it is exposed to severe weathering.
PVC Nitrile
PVC Nitrile provides premium performance and long-term reliability in very harsh and corrosive environments.
Their exceptional resistance to heat aging and a broad range of fuels, solvents and chemicals makes them ideal for
many demanding aerospace, automotive and industrial applications. Fluoroelastomers also offer excellent resistance
to weather, ozone, oxygen and sunlight and are inherently more flame retardant than hydrocarbon rubbers.
Fluoroelastomers have poor resistance to ketones, ester, ethers, amines and aqueous bases (e.g., ammonia and
sodium hydroxide).
Thermoplastic Elastomers (TPE)
TPE are materials that have the properties and performance of rubber but are processed like thermoplastics. Their
performance properties are similar to conventional thermosets such as EPDM or neoprene. The important features of
TPE are that they are flame resistant and possess resistance to aliphatic and aromatic hydrocarbon solvents, as
well as oil and gasoline.
PVC
PVC has excellent impact strength, good resilience, tensile strength, abrasion resistance and maintains
flexibility at lower temperatures. It is not the polymer of choice when resistance to oil, gasoline and
hydrocarbon solvents is required.
Polycarbonate
Polycarbonate is naturally transparent, with the ability to transmit light nearly that of glass. It has high
strength, toughness, heat resistance, and excellent dimensional and color stability. Flame retardants can be added
to polycarbonate without significant loss of properties. It has only fair chemical resistance and is attacked by
many organic solvents. It is also expensive compared to other plastics.