The document discusses nitrile rubber, which is a polymeric mixture of butadiene and acrylonitrile in a 2:1 ratio. Higher levels of acrylonitrile yield properties like low temperature flexibility and increased hardness. Nitrile rubber is a highly polar elastomer that exhibits large and reversible elastic deformation. It has excellent tensile strength, elongation, low temperature flexibility, compression set, tear resistance, and abrasion resistance. However, it has fair to poor flame resistance and gas permeability.

2.  Polymeric mixture of butadiene and
acrylonitrile in the respective ratio 2:1.
 Ratios can be varied to change physical
properties...higher levels of acrylonitrile
yield low temperature flexibility, and
increase compound hardness
 Highly polar elastomer (large and
reversible elsatic deformation)

3. Excellent Good Fair Poor
Tensile strength •
Elongation •
Low temperature flexibility •
Compression Set •
Tear resistance •
Abrasion resistance •
Flame resistance •
Gas permeability •

4. Excellent Good Fair Poor
Water •
Petroleum oil •
Silicone lubricants •
Dilute acids •
Dilute alkalis •
Hydraulic fluids •
Transmission fluid •
Steam •
Ozone •
Weather •
Ketones •
Strong acids •
Brake fluid •

5.  Vibration Control of
horizontal forces up to
125 tons
 O Rings, gaskets,
sealants, grommets and
tubing pads
 Frequently used in
automotive air
conditioning systems
employing R-134a
refrigerants

6.  Nitrile should not be exposed to
› direct sunlight
› moderate to high levels of atmospheric
ozone
› oxygen
 Must be used in a closed system

7.  Nitrile accepts
antidegradants, which
improve the
aforementioned
properties
› PVC (polyvinyl chloride)
› Hydrogenation

8.  High tensile strength
 Low permanent set
 Good abrasion resistance
 High elasticity
 Stability toward thermal ageing
 Better properties at low temperatures

9.  Nitrile rubber is hydrogenated in solution
using precious metal catalysts
 Carbon-carbon bonds are converted to
more stable single bonds (controls
different states)
 Can be crosslinked using sulphur and
peroxide cure systems

10. Nitrile
 1/32” thick $14.80 per
square yard
 ¼” thick $72.20 per
square yard
Hydrogenated Nitrile
 2 to 3 times more
expensive than the
conventional
polychloroprene used
now
 New features will allow
it to last 5.5 times
longer