be replaced?

Ivory is a variety of dentin,
and is found in elephants tusks as well as hippopotamus, walrus and
sperm whale teeth. Ivory was primarily obtained from the hunting of
elephants.  It was used for many things such as billiard balls,
piano keys, sculptures and knife handles because it was easy to carve,
durable and beautiful.  Ivory was considered an item of luxury
because of its rarity and difficulty to obtain. The numbers of elephants
were limited and dwindling, and from each elephant killed only a small
amount of ivory was obtained.  It was also costly to import the
ivory from overseas.  (KCPC, 2003; Lister, 2003)

The hunting of elephants
was causing a severe ecological and environmental problem.  If
a replacement for ivory was not found, elephants would soon become extinct. 
Early ivory poachers usually killed male adult elephants because their
tusks were larger, leading to an imbalance between the sexes of elephant
populations, hampering their ability to reproduce and sustain their
populations.  (WWF, 2003)  Also the high cost of obtaining
ivory made it a rare resource unable to be widely used.  By 1863
there was a worldwide shortage of ivory, with one company even offering
a $10,000 prize for the patent rights for a substitute that was suitable
to use to produce billiard balls. (KCPC, 2003; Lister, 2003)

What is used as an alternative?

The first replacement for
ivory was cellulose nitrate (celluloid) which was a semi-synthetic polymer
developed in 1869 by John W. Hyatt.  However, cellulose nitrate
was very unstable and highly flammable.  Due to this the collision
of two billiard balls made of celluloid sometimes resulted in a small
explosion.  Because of this instability, celluloid was not a viable
replacement for ivory, and hence another plastic was developed. (Lister,
2003; Carrotbox.com, 2003)

Bakelite (Phenol Formaldehyde),
the first fully synthetic polymer, created by Belgian chemist Dr. Leo
Baekeland in 1907, was a chemically stable, non-flammable replacement
for ivory.  Bakelite is a phenolic resin which is thermosetting
(meaning that it can be molded only once).  Bakelite was one of
the first plastics to be used in mass manufacturing.  (Lister,
2003; KCPC, 2003; Thompson, 2003)

Bakelite is created by
a polymerization process between phenol and formaldehyde heated together. 
It is a condensation polymer.  The following equation illustrates
the polymerization process:

Source:
KCPC, 2003

The result of this polymerization
is a hard, rigid plastic made of crosslinked polymer chains.  The
application of heat first softens the plastic but the polymer then cross-links
and hardens permanently.  (KCPC, 2003; Thompson, 2003) 

Bakelite is produced industrially
by creating phenolic resin, as shown in the equation above.  It
is molded in to blocks, allowed to cool and then ground in to a fine
powder.  Then fillers (such as cotton or fine sawdust) are added,
along with pigments for colour.  Catalysts and other chemicals
are added which allow the polymer to be more easily molded, and the
powder mix is then remelted and rolled into flat sheets by hot rollers. 
It is then once again ground in to a powder which is used to manufacture
products made of the plastic.  (Thompson, 2003; Fadem, 2003)

Bakelite was shaped by
either pouring a slightly chemically modified molten substance in to
casts, or by molding the fine Bakelite powder under high heat and high
pressure in to the form desired.  Bakelite was also able to be
carved in to the desired shape in a similar way to which ivory was carved. 
(Fadem, 2003)

Bakelite could be colored
during the production process, making it more appealing as a replacement
for ivory in jewelry or ornaments.  By altering the pigment a transparent
or translucent effect could be produced.  A marbleized effect could
be produced by mixing colors. (Fadem, 2003)

How has this alternative solved problems associated with the use of
the natural resource?

Bakelite could be produced
cheaply, hence making it far more economical than ivory.  The accessible
price of Bakelite, as well as its ability to be carved and coloured,
meant that it was widely used for ornamentation and jewelry from 1910
onwards.  During the depression Bakelite sold more than any other
commercial product, becoming a standard material used to manufacture
many household items such as radios and kitchen utensils, as well as
things that were traditionally made from ivory, such as billiard balls
and decorative buttons.  Bakelite is an economical replacement
for ivory, and also solved the supply problems associated with ivory
use.  (Fadem, 2003; KCPC, 2003)

Despite the discovery of
Bakelite and other plastics, poaching of elephants for their ivory is
still a problem in many parts of the world.  Ivory is still valued
and sought after, and because of this, elephants are still endangered
species, and ivory hunting and use is still a much debated environmental
issue today.  Elephant numbers have been continually declining,
even since the development of synthetic ivory replacements.  However,
legislation is working to help protect elephant populations, and ivory
demand has decreased due to heightened environmental awareness in society. 
(WWF, 2003)  The development of Bakelite has meant that ivory does
not need to be used for products, however it is still a desired natural
material, and is highly prized and valued.  The use of Bakelite
(and other plastic products developed in more recent times) has reduced
ivory demand however, and hence the ecological damage caused by obtaining
ivory has also been somewhat reduced.

Bibliography

Key Centre for Polymer
Colloids (KCPC) Case Study: Ivory and Bakelite (WWW)

Accessed 31/8/03

http://www.kcpc.usyd.edu.au/discovery/9.5.1/9.5.1_ivory.html

S. Fadem, M.D.  Bakelite: A Revolutionary
Early Plastic (WWW) Accessed 31/8/03

http://www.deco-echoes.com/bakelite.html

Ted Lister  Conservation Chemistry (WWW) Accessed 31/8/03

http://www.chemsoc.org/pdf/learnnet/conservtnplastics.pdf

Carrotbox.com Plastic Types and History (WWW) Accessed 31/8/03

http://www.thecarrotbox.com/plastic/

Tony Thompson Amazing Bakelite (WWW) Accessed 2/9/03

http://www.burdaleclose.freeserve.co.uk/new_page_8.htm

World Wildlife Fund (WWF) Elephants in the
Balance (WWW) Accessed 2/9/03

http://www.panda.org/resources/publications/species/elephants/