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IndiaRubberDirectory.com > Rubber Engineering > Rubber Properties |
General characteristics of common polymers
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Buna-N
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Neoprene
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Common Names
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Buna-N, Nitrile, NBR
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Neoprene®
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ASTM D-2000 Classification
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BF, BG, BK
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BC, BE
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Military (MIL STD 417)
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SB
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SC
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Chemical Definition
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Butadiene Acrylonitrile
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Polychloroprene
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General Characteristics
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Durometer
Range (Shore A)
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20 - 95
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20 - 95
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Tensile Range (P.S.I.)
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200 - 3000
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500 - 3000
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Elongation (Max %)
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600
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600
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Compression Set
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Good
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Good
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Resilience - Rebound
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Good
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Excellent
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Abrasion Resistance
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Excellent
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Excellent
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Tear Resistance
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Good
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Good
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Solvent Resistance
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Good to Excellent
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Fair
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Oil Resistance
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Good to Excellent
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Fair
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Low Temperature Usage (F°)
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+30° to -40°
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+10° to -50°
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High Temperature Usage (F°)
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to 250°
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to 250°
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Aging Weather - Sunlight
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Poor
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Good
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Adhesion to Metals
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Good to Excellent
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Good to Excellent
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Comment
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Nitrile (Buna-N) is a
general purpose oil resistant polymer
which has good solvent, oil, water and
hydraulic fluid resistance, good
compression set, abrasion resistance and
tensile strength.
Nitrile should not be used
in highly polar solvents such as acetone
and MEK, ozone, chlorinated hydrocarbons
and nitro hydrocarbons.
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Neoprene is an all purpose
polymer with many desirable
characteristics. It has additional plus
features: high resilience with low
compression set; flame resistant;
compounds free of sulfur are easily made;
and animal and vegetable oil resistant
generally not affected by moderate
chemicals, fats, greases and many oils and
solvents.
Neoprene is generally
attacked by strong oxidizing acids,
esters, ketones, chlorinated aromatic and
nitro hydrocarbons.
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Silicone
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Common Names
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Silicone
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ASTM D-2000 Classification
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CA
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FC, FE, GE
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Military (MIL STD 417)
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RS
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TA
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Chemical Definition
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Polysiloxane
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General Characteristics
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Durometer
Range (Shore A)
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30 - 90
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30 -90
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Tensile Range (P.S.I.)
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500 -3000
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200 - 1500
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Elongation (Max %)
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600
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700
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Compression Set
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Good
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Good
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Resilience - Rebound
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Good
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Good
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Abrasion Resistance
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Good
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Fair to Poor
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Tear Resistance
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Fair
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Poor
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Solvent Resistance
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Poor
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Poor
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Oil Resistance
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Poor
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Fair to Poor
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Low Temperature Usage (F°)
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-20° to -60°
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-60° to -150°
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High Temperature Usage (F°)
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to 350°
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to 450°
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Aging Weather - Sunlight
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Excellent
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Excellent
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Adhesion to Metals
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Fair to Good
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Good
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Comment
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Ethylene Propylene is a
polymer with outstanding properties. It
has exceptionally good weather aging and
ozone resistance; excellent water and
chemical resistance; excellent resistance
to gas permeability and excellent
resistance to aging due to exposure to
steam; and heat resistance excellent up to
350°F. Ethylene Propylene is a polymer
where oil and solvent resistance is poor,
however, it is fairly good in ketones and
alcohols.
Ethylene Propylene is not
recommended for food applications or
exposure to aromatic hydrcarbons.
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Silicone Rubber has a great
many variations and can be compounded to
meet any number of applications. Silicone
can be compounded to have tensile in the
area of 1500 PSI and tear upto 200 lbs.;
low compression set and good resilience;
moderate solvent resistance; excellent
heat resistance; good release
characteristics; extreme low temperature
properties; and can be highly resistant to
oxidation and ozone attack
Silicone is generally
attacked by most concentrated solvents,
oils, concentrated acids and dilute sodium
hyrdoxide..
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Fluorosilicone |
Fluoro Elastomers |
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Common Names |
Fluorosilicone |
Fluoro Elastomers |
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ASTM D-2000
Classification |
FK |
HK |
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Military (MIL STD 417) |
MIL-R-25988, Ammend. 2 |
MIL-R-25897 and
MIL-R-83248 |
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Chemical Definition |
Fluorosilicone |
Fluorinated Hydrocarbon |
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General Characteristics |
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Durometer
Range (Shore A) |
50 - 80 |
60 - 90 |
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Tensile Range (P.S.I.) |
500 - 800 |
500 - 2000 |
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Elongation (Max %) |
300 |
300 |
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Compression Set |
Good |
Good |
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Resilience - Rebound |
Excellent |
Fair |
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Abrasion Resistance |
Poor |
Good |
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Tear Resistance |
Poor |
Good |
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Solvent Resistance |
Fair |
Excellent |
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Oil Resistance |
Good |
Excellent |
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Low Temperature Usage
(F°) |
-80° |
+10° to -10° |
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High Temperature Usage
(F°) |
300° |
400° to 600° depending
on time and service condition |
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Aging Weather -
Sunlight |
Excellent |
Excellent |
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Adhesion to Metals |
Poor |
Good |
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Comment |
Fluorosilicone is
considerably more expensive than
silicone, however it is developed for
special applications where general
resistance to oxidizing chemical,
aromatic and chlorinated solvent bases
is required.
Fluorosilicone is not
recommended and is generally attacked
when exposed to brake fluids,
hydrazine and ketones. Fluorosilicone
should not be confused with silicone
in regard to high heat resistance. |
Fluoro Elastomers have
high heat resistance up to 600°F, and
resistance to a wide reange of oils
and solvents; especially all
aliphatic, aromatic and halogenated
hydrocarbons, acids, animal and
vegetable oils.
Fluoro Elastomers are
not recommended for ketones, low
molecular weight esters and nitro
containing compounds. |
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Natural Rubber |
SBR |
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Common Names |
Natural Rubber |
SBR, GRS |
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ASTM D-2000
Classification |
AA |
AA, BA |
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Military (MIL STD
417) |
RN |
RS |
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Chemical Definition |
Polyisoprene |
Styrene Butadiene |
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General
Characteristics |
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Durometer
Range (Shore A) |
20 - 100 |
30 - 100 |
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Tensile Range (P.S.I.) |
500 - 3500 |
500 - 3000 |
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Elongation (Max %) |
700 |
600 |
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Compression Set |
Excellent |
Good |
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Resilience -
Rebound |
Excellent |
Good |
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Abrasion Resistance |
Excellent |
Excellent |
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Tear Resistance |
Excellent |
Fair |
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Solvent Resistance |
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