Materials Used
Rubbers or elastomers are mixed with various chemicals in order to provide the reinforcement and curing ingredients required to produce the physical properties necessary for the service conditions.
A wide choice of basic polymers (rubbers) is available. Many of these rubbers can be blended or compounded to obtain the desired properties based on the application.
ASTM
Designation
D1418-79
|
Common
Name
|
Composition
|
General Properties
|
NR |
Natural |
Isoprene, natural |
Excellent physical properties including abrasion and low temperature resistance. Poor resistance to petroleum-based fluids |
IR |
Polyisoprene |
Isoprene, synthetic |
Similar to natural rubber |
SBR |
SBR |
Styrene-butadiene |
Good physical properties and abrasion resistance. Poor resistance to petroleum-based fluids. |
CR |
Neoprene |
Chloroprene |
Good weathering resistance. Flame retarding. Moderate resistance to petroleum-based fluids. Good physical properties. |
NBR |
Buna N |
Nitrile-butadiene |
Excellent resistance to petroleum-based fluids. Good physical properties. |
IIR |
Butyl |
Isobutene-Isoprene |
Very good weathering resistance. Excellent dielectric properties. Low permeability to air. Good physical properties. Poor resistance to petroleum-based fluids. |
EPDM |
Ethylene-propylene rubbers
|
Ethylene-propylene-diene |
Excellent ozone, chemical and aging resistance. Poor resistance to petroleum-based fluids. |
FKM |
Viton®, Flourel® |
Hexafluro-propylene-vinyl idene fluoride |
Excellent oil and air resistance at both high and low temperatures. Very good chemical resistance. |
Source: Rubber Manufacturers Association Sheet Rubber Handbook, Third Edition