Metallurgy and Materials Engineering Department, University of Punjab Lahore

1. Polybutadiene

2. Polybutadiene
Polybutadiene [butadiene rubber BR] is a synthetic rubber. Polybutadiene rubber is a
polymer formed from the polymerization of the monomer 1,3-butadiene.
Polybutadiene has a high resistance to wear and is used especially in the manufacture
of tires, which consumes about 70% of the production. Another 25% is used as an
additive to improve the toughness (impact resistance) of plastics such as polystyrene
and acrylonitrile butadiene styrene.

3. History
 The Russian chemist Sergei Vasilyevich Lebedev was the first to
polymerize butadiene in 1910. In 1926 he invented a process for manufacturing
butadiene from ethanol, and in 1928, developed a method for producing
polybutadiene using sodium as a catalyst.

4. Chemistry and Manufacturing Process
Polybutadiene is a homopolymer (only one monomer) of 1,3 butadiene,
a monomer containing four carbon atoms, and six hydrogen atoms
(C4H6). The four carbon atoms are in a straight chain containing two
“double bonds” as follows:
CH2 = CH-CH =CH3
1,3 butadiene
It is the double bonds that are the key to polymer formation. They are
attacked by catalysts to maintain a repetitive chain growth process
which continues until something is added to terminate the reaction at
the desired molecular weight.

5. Production
The annual production of polybutadiene was 2.0 million tons in
2003.This makes it the second most produced synthetic rubber by
volume, behind the styrene-butadiene rubber (SBR).
The production processes of high cis polybutadiene and low cis
used to be quite different and were carried out in separate plants.
Lately, the trend has changed to use a single plant to produce as
many different types of rubber as possible, including, low cis
polybutadiene, high cis (with neodymium used as a catalyst) and
SBR.

6. Properties of polybutadiene
•High Elasticity
•Low temperature properties
•Wear resistance
•Low hysterisis
•Good flexibility at ambient temperatures
•High abrasion resistance in severe conditions
•Low rolling resistance

7. Applications
 Tyres:Polybutadiene is largely used in various parts of automobile tires; the manufacture of tires consumes about 70% of
the world production of polybutadiene.
 Plastics: bout 25% of the produced polybutadiene is used to improve the mechanical properties of plastics, in particular of
high-impact polystyrene.
 Golf Ball: Most golf ball are made of an elastic core of polybutadiene surrounded by a layer of a harder material.
 Polybutadiene rubber may be used in the inner tube of hoses for sandblasting, along with natural rubber.
 This rubber can also be used in railway pads, bridge blocks. And many more