Materials

Polymers

Advantages:
Butyl is noted for its outstanding impermeability to gases and vapors and is frequently used in air retaining applications. It can possess very good resistance to heat, oxygen, ozone and sunlight. In addition, it can provide excellent resistance to alkalis, acids and oxygenated solvents. It has high energy absorption and can be a good electrical insulator.

Limitations:
Butyl is not recommended for uses requiring resistance to oil, gasoline and hydrocarbon solvents. Butyl products may be difficult to process.

Polymers

Advantages:
CSM (Hypalon®, Chlorosulfonated Polyethylene) is recognized for outstanding resistance to abrasion. It can offer good resistance to deterioration from ozone, sunlight, and oxidation. CSM moderately resists oils and corrosive chemicals. It can exhibit good color stability and flame resistance.

Limitations:
CSM (Hypalon®, Chlorosulfonated Polyethylene) is more expensive than most general-purpose elastomers. It is not the polymer of choice for applications in contact with fuels, aromatic solvents and hot oils. Usually CMS does not have excellent resilience and compression set resistance.

Polymers

Advantages:
EPDM (Ethylene Propylene Diene Monomer) elastomers can be formulated for excellent resistance to ozone, oxygen, heat degradation and is often recommended for outdoor applications. It can display very good resistance to water, steam, alkalis, acids, and oxygenated solvents. EPDM has good low temperature flexibility and is both sulfur and peroxide curable.

Limitations:
EPDM (Ethylene Propylene Diene Monomer) is not recommended for uses requiring resistance to oil, gasoline and hydrocarbons. EPDM displays limited compression set resistance and offers poor adhesion to fabrics and metals.

Polymers

Advantages:
Epichlorohydrin (ECO, CO) is a specialty elastomer that can be compared to Nitrile in regards to solvent resistance (outstanding resistance to oils, fuels and petroleum based hydraulic fluids) but contains the added benefits of good ozone, sunlight and oxidation resistance. It can demonstrate very low gas permeability and good heat resistance.

Limitations:
Generally, Epichlorohydrin compounds are more expensive than Nitriles. It is not suitable for use in steam, ketones, esters and chlorinated solvents.

Polymers

Advantages:
Fluoroelastomers (Viton®, FKM) are specialty elastomers that are formulated for outstanding resistance to extreme heat, oil, gasoline, hydraulic fluids, and hydrocarbon solvents. They possess very good resistance to oxygen, ozone, sunlight and provide good impermeability to gases and vapor. Viton® is a common fluoroelastomer and is a registered trademark of DuPont.

Limitations:
Fluoroelastomers are not generally resistant to oxygenated solvents and can display poor tear resistance. They are limited by low temperature serviceability and are priced at a premium.

Polymers

Advantages:
Fluorosilicone (FSI, FVMQ) is a specialty elastomer that contains the environmental stability and excellent resistance to temperature extremes similar to that of Silicone. Added benefits include excellent fuel, oil, solvent and chemical resistance.

Limitations:
Fluorosilicone (FSI, FVMQ) can be one of the most expensive polymers. Comparable to Silicone, Fluorosilicone is limited by an average tensile strength and poor flex resistance. In some applications Fluorosilicone is not suitable for use in brake fluids, hydrazine and ketones.

Polymers

Advantages:
HNBR (Hydrogenated Nitrile Butadiene Rubber) is a specialty polymer with high physical properties. It is tough and abrasion resistant. It can display excellent resistance to oil, solvents, and hydraulic fluids. HNBR has good ozone, oxidation and chemical resistance.

Limitations:
HNBR (Hydrogenated Nitrile Butadiene Rubber) is not recommended for uses involving high polar fluids, aromatic, or chlorinated hydrocarbons. It has a limited continuous service temperature range and can be costly.

Polymers

Advantages:
Natural Rubber (Polyisoprene, NR) exhibits excellent abrasion resistance, tensile strength and resilience. It provides exceptional adhesion to fabrics and metals and has good low temperature flexibility. Natural Rubber is generally resistant to moderate chemicals, alcohols, ketones and aldehydes.

Limitations:
Natural Rubber (Polyisoprene, NR) is not suitable for applications involving outdoor exposure (ozone, heat, and oxygen resistance). Natural Rubber offers poor resistance to corrosive chemicals, petroleum derivatives, fats and non-polar solvents.

Polymers

Advantages:
For general-purpose applications Neoprene (Polychloroprene, Chloroprene, CR) is noted for its versatility. It can display very good resistance to ozone, oxygen, sunlight, alkalis and acids. Neoprene inherently demonstrates good flame resistance. It can offer good tensile strength, resilience and moderate oil and gasoline resistance.

Limitations:
While Neoprene (Polychloroprene, Chloroprene, CR) offers moderate oil resistance it is not recommended for demanding fuel and hot oil applications. It exhibits poor to fair resistance to aromatic and oxygenated solvents. Neoprene is also limited by low temperature flexibility.

Polymers

Advantages:
For general-purpose applications requiring oil resistance Nitrile (Butadiene Acrylonitrile, BUNA N, NBR) is the polymer of choice. It has outstanding resistance to oil, gasoline, petroleum based hydraulic fluids and hydrocarbon solvents. In addition, it can offer good resistance to alkalis and acids. Nitrile can be formulated to have a wide range of service temperatures.

Limitations:
Nitrile (Butadiene Acrylonitrile, BUNA N, NBR) is not recommended for applications involving exposure to ozone, weathering, heat and sunlight. It offers poor resistance to polar solvents such as esters, ketones, chlorinated solvents, or nitro carbons.

Polymers

Advantages:
PVC (Polyvinyl Chloride, Vinyl) can be formulated with many additives to meet an assortment of specific end-uses. It is versatile and cost effective. Generally, PVC is strong, resilient, electrically non-conductive and moisture resistant. It has good flame resistance and will self-extinguish when a flame is removed. PVC materials are available in a wide variety of colors.

Limitations:
PVC (Polyvinyl Chloride, Vinyl) is restricted by poor low temperature properties. When subjected to high heat and mechanical stress PVC is not recommended because the elastomer becomes soft and flexible. Extended exposure to sunlight will cause colors to fade.

Polymers

Advantages:
SBR (Styrene Butadiene Rubber) is a synthetic general-purpose rubber with properties similar Natural Rubber. It is a low-cost polymer and can display excellent impact and tensile strength. It has good resilience, abrasion resistance, and low temperature flexibility.

Limitations:
SBR’s (Styrene Butadiene Rubber) limitations are similar to Natural Rubber. It is restricted by ozone, sunlight, oil, gasoline and hydrocarbon solvents.

Polymers

Advantages:
Silicone (SI, VMQ) is a specialty elastomer that is known for its serviceability over a wide temperature range. Silicone compounds can show excellent resistance to ozone, weathering, oxidation, compression set and moderate chemical resistance. Its high degree of biocompatibility makes Silicone ideal for the medical industry. Silicone generally has good vibration dampening properties and overall good dynamic properties at elevated temperatures.

Limitations:
Silicone (SI, VMQ) is commonly restricted by average tensile strength and poor resistance to fuels, solvents, abrasion and flexing. It usually has high permeability to gases and can be expensive.

Polymers

Advantages:
Urethane (Polyurethane, EU) can be compounded to display excellent resistant to ozone, sunlight, moderate chemicals, fats, oils and greases. It has outstanding resistance to abrasion and can demonstrate very high tensile strength with good elongation. Urethane adheres well to metals and fabrics.

Limitations:
Urethane (Polyurethane, EU) is generally attacked by alkalis, acids and oxygenated solvents. It usually exhibits poor compression set resistance and can be costly.