Page 247 - Carrahers_Polymer_Chemistry,_Eighth_Edition

210 Carraher’s Polymer Chemistry

6.7 POLY(VINYL CHLORIDE)

Poly(vinyl chloride) is one of the three most abundantly produced synthetic polymers. PVC is one of
the earliest produced polymers. In 1835, Justus von Liebig and his research student Victor Regnault
reacted ethylene dichloride with alcoholic potash forming the monomer vinyl chloride. Latter
Regnault believed he polymerized vinyl chloride but latter studies showed it to be poly(vinylidene
chloride). In 1872, E. Baumann exposed vinyl chloride sealed in a tube to sunlight and produced a
solid, PVC. Klasse, in Germany, found that vinyl chloride could be made by addition of hydrogen
chloride to acetylene in a system that could be scaled up for commercial production. (Today, most
vinyl chloride is made from the oxychlorination reaction with ethylene.) By World War I, Germany
was producing a number of flexible and rigid PVC products. During World War I, Germany used

PVC as a replacement for corrosion-prone metals.
Today, PVC is made from the polymerization of vinyl chloride as shown in Equation 6.58.

H C R
2
R
Cl (6.58)
Cl
Waldo Semon was responsible for bringing many of the PVC products to market. As a young
scientist at BF Goodrich, he worked on ways to synthesize rubber and to bind the rubber to metal.
In his spare time he discovered that PVC, when mixed with certain liquids, gave a elastic-like, pli-

able material that was rain proof, fire resistant, and that did not conduct electricity. Under the trade
name Koroseal, the rubbery material came into the marketplace, beginning about 1926, as shower
curtains, raincoats, and umbrellas. During World War II, it became the material of choice to protest
electrical wires for the Air Force and the Navy. Another of his inventions was the synthetic rubber
patented under the name Ameripol that was dubbed “liberty rubber” since it replaced natural rubber
in the production of tires, gas masks, and other military equipment. Ameripol was a butadiene-type
material.
Because of its versatility, some unique performance characteristics, ready availability, and low cost
PVC is now the third largest produced synthetic polymer behind polyethylene and polypropylene.
As a side note, today there is a debate concerning the use of chlorine-containing materials and
their effect on the atmosphere. This is a real concern and one that is being addressed by industry.
PVC, and other chloride-containing materials have in the past been simply disposed of through
combustion that often created unwanted hydrogen chloride. This practice has largely been stopped
but care should be continued to see that such materials are disposed of properly. Further, simply
outlawing of all chloride-containing materials is not possible or practical. For instance, we need
common table salt for life and common table salt is sodium chloride. Chlorine is widely used as a
water disinfectant both commercially (for our drinking water) as well as for pools. Further, PVC
is an important material that is not easily replaced. Finally, the amounts of chloride-containing
residue that is introduced into the atmosphere naturally is large in comparison to that introduced
by PVC. Even so, we must exercise care as we want to leave a better world for our children and

grandchildren, so a knowledge-based approach must be taken. As with most significant problems, it
is better to error in the direction of caution.
Another health concern is the presence of certain plasticizers. As noted below, PVC employs a
large amount of additives, including a variety of plasticizers. We do not live in a risk-free society but
some risks should be eliminated or minimized. One group of plasticizers of interest is the phthal-
ate plasticizers. As with other health concerns infant care is of greatest concern. Vinyl IV bags
are often used in neonatal intensive care units. Food and Drugs Association (FDA) has requested
that manufacturers eliminate the use of questionable plasticizers for the production of these bags.
Another answer is simply eliminating vinyl IV bags using another material for construction of these

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