Chemistry Reference
In-Depth Information
BUTADIENE DERIVATIVES
Hydrogen cyan
ide
H
2
N
CH
2
CH
2
CH
2
CH
2
CH
2
CH
2
NH
2
(hexamethylenediamine)
Hydrogen
Cl
Chlorine
CH
2
C
CH
CH
(chloroprene)
2
Catalyst
Cyclooctadiene (8-membered ring)
Catalyst
Cyclododecatriene
(12-membered ring)
CH
2
CH
CH
CH
2
CO
Maleic anhydri
de
(tetrahydrophthalic anhydride)
O
CO
Catalyst
(CH
2
CH
CH
CH
)
x
(polybutadiene)
2
Styrene
(CH CHCHCH
2
CH
CH
)
x
(styrene-butadiene rubber)
2
2
O
Natural
rubber latex
, obtained from rubber trees, is converted to its final
form by a process known as “vulcanization,” first discovered by Charles
Goodyear in 1839. Vulcanization is basically a
crosslinking
reaction of
double bonds in the latex structure with sulfur. The polymerization of buta-
diene with itself or with other vinyl monomers results in a material that like
natural latex, still contains double bonds. Thus,
synthetic rubber
made from
butadiene can be processed and vulcanized just like natural rubber.
The first use of butadiene to make synthetic rubber was demonstrated in
Russia in 1910 by S.V. Lebchev, who also developed a synthesis of butadiene
from ethanol obtained by fermentation.
The first important commercial synthetic rubber was poly(chloroprene)
which was made available for sale as “Neoprene” by DuPont in 1931. It is
still made and sold today because of its superior resistance to oils, sunlight,
and oxygen (ozone).
