Properties
of rubber type

Natural rubber
NR

SBR

Butyl rubber
IIR

Material designation

AA

AA

AA

Tensile strength

non black filled

20.7

6.9

10.3

carbon black filled

20.7

13.8

13.8

Hardness range

30-90

40-90

40-75

Spec. gravity

0.93

0.94

0.92

Adhesion to metals

excellent

excellent

good

Adhesion to fabrics

excellent

good

good

Tear strength

good to very good

moderate

good

Abrasion resistance

excellent

good to excellent

good

Compression set

good

good

moderate

Rebound resilience

at room temperature

excellent

good

slight

in the warmth

excellent

good

very good

Dielectric properties

excellent

excellent

excellent

Electr. insulating resistance

good to excellent

good to excellent

good to excellent

Gas permeability

quite good

quite low

very low

Resistance to acids

diluted

moderate to good

moderate to good

excellent

concentrated

moderate to good

moderate to good

good

Resistance to solvents

aliphatic hydrocarbons

slight

slight

slight

aromatic hydrocarbons

slight

slight

slight

oxygenous solvents

moderate to good

good

good

paint solvents

slight

slight

moderate to good

Resistance to:

lubricating oils

slight

slight

slight

mineral oil and fuels

slight

slight

slight

animal and vegetable oils

slight to good

slight to good

very good

water absorption

very good

good to very good

very good

oxidation

good

moderate

excellent

ozone

slight to moderate

slight

excellent

sunlight

slight

slight

very good

thermal ageing

85° C

90° C

120° C

effects of flames

slight

slight

slight

high temperatures

good

moderate to good

very good

exposure to cold

excellent

very good

good