Cellulose Based Plastics: Celluloid and Rayon
All Goodyear had done with vulcanization was improve the
properties of a natural polymer. The next logical
step was to use a natural polymer, cellulose, as the basis
for a new material.
Inventors were particularly interested in developing
synthetic substitutes for those natural materials that were
expensive and in short supply, since that meant a
profitable market to exploit. Ivory was a
particularly attractive target for a synthetic
replacement.
An Englishman named Alexander Parkes developed a
"synthetic ivory" named "pyroxlin," which he marketed
under the trade name "Parkesine," and which won a bronze
medal at the 1862 World's Fair in London. Parkesine
was made from cellulose treated with nitric acid and a
solvent. The output of the process hardened into a
hard, ivory-like material that could be molded when
heated.
However, Parkes was not able to scale up the process to an
industrial level, and products made from Parkesine quickly
warped and cracked after a short period of use. An
American printer and amateur inventor named John Wesley
Hyatt took up where Parkes left off. Parkes had
failed for lack of a proper solvent, but Hyatt discovered
that camphor would do the job very nicely.
Hyatt was something of an industrial genius who understood
what could be done with such a shapeable, or "plastic,"
material, and proceeded to design much of the basic
industrial machinery needed to produce good-quality
plastic materials in quantity. Since cellulose was
the main constituent used in the synthesis of his new
material, Hyatt named it "celluloid." It was introduced in
1863.
One of the first products was dental pieces. Sets of
false teeth built around celluloid proved cheaper than
existing rubber dentures. However, celluloid
dentures tended to soften when hot, making tea drinking
tricky, and the camphor taste tended to be difficult to
suppress.
Celluloid's real breakthrough products were waterproof
shirt collars, cuffs, and the false shirt fronts known as
"dickies," whose unmanageable nature later became a stock
joke in silent-movie comedies. They didn't wilt and
didn't stain easily, and Hyatt sold them by trainloads.
Corsets made with celluloid stays also proved popular,
since perspiration didn't rust the stays, as it would if
they had been made of metal.
Celluloid proved extremely versatile in its fields of
application, providing a cheap and attractive replacement
for ivory, tortoise-shell, and bone. Traditional
products that had used these materials were much easier to
fabricate with plastics. Some of the items made with
cellulose in the 19th century were beautifully designed
and implemented. For example, celluloid combs made
to tie up the long tresses of hair fashionable at the time
are now jewel-like museum pieces. Such pretty
trinkets were no longer only for the rich.
Celluloid could also be used in entirely new applications.
Hyatt figured out how to fabricate the material in a strip
format for movie film. By the year 1900, movie film
was a major market for celluloid.
However, celluloid still tended to yellow and crack over
time, and it had another, more dangerous defect: it burned
easily and spectacularly, unsurprising given that mixtures
of nitric acid and cellulose are also used to synthesize
smokeless powder.
Ping-pong balls, one of the few products still made with
celluloid, sizzle and burn if set on fire, and Hyatt liked
to tell stories about celluloid billiard balls exploding
when struck very hard. These stories might have had
a basis in fact, since the billiard balls were often
celluloid covered with paints based on another, even more
flammable, nitrocellulose product known as "collodion."
If the balls had been imperfectly manufactured, the paints
might have acted as primer to set the rest of the ball off
with a bang.
Cellulose was also used to produce cloth. While the
men who developed celluloid were interested in replacing
ivory, those who developed the new fibers were interested
in replacing another expensive material, silk.
In 1884, a French chemist, the Comte de Chardonnay,
introduced a cellulose-based fabric that became known as
"Chardonnay silk." It was an attractive cloth, but
like celluloid it was very flammable, a property
completely unacceptable in clothing. After some
ghastly accidents, Chardonnay silk was taken off the
market.
In 1894, three British inventors, Charles Cross, Edward
Bevan, and Clayton Beadle, patented a new "artificial
silk" or "art silk" that was much safer. The three
men sold the rights for the new fabric to the French
Courtald company, a major manufacturer of silk, which put
it into production in 1905, using cellulose from wood pulp
as the "feedstock" material.
Art silk became well known under the trade name "rayon,"
and was produced in great quantities through the 1930s,
when it was supplanted by better artificial fabrics.
It still remains in production today, often in blends with
other natural and artificial fibers. It is cheap and
feels smooth on the skin, though it is weak when wet and
creases easily. It can also be produced in a
transparent sheet form known as "cellophane."
Plastic
Polymers | Celluloid &
Rayon | Bakelite |
Polystyrene & PVC |
Nylon
Synthetic
Rubber | A
Plastics Explosion |
Plastic Recycling |
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