DEVELOPING AND DESIGNING NEW CHEMICALS AND MATERIALS - Chemistry: Notable Research and Discoveries - page 15

most trials, the result will probably not be a very palatable dish, but once
in a while the chef may hit upon the gourmet equivalent of a jackpot.
The same trial-and-error process occurs in materials science. Some-
times researchers need to devise a method to manufacture a substance
that theory has suggested may exist, given the right conditions. In other
cases, an engineer or manufacturer may need a substance with specific
properties, such as hardness or the ability to dissolve in certain liquids,
and no known substances meet all the requirements. Lacking a specific
set of instructions on how to make new materials, scientists of the past
have relied on a little bit of inspiration—their knowledge of chemical
principles, for instance—and a lot of perspiration as they try and try
again, as Bessemer described in his autobiography.
Plastics are one example. Scientists use the term plastic to refer to
polymers, which are materials composed of a chain of bonded mole-
cules. For instance, most credit cards are made from a plastic known
as polyvinyl chloride (PVC), which consists of linked molecules of
vinyl chloride. (Old “vinyl” record albums were often made from the
same material.) The first plastic made entirely in the laboratory (as op-
posed to natural products) was Bakelite, concocted around 1908 by the
Belgian-American chemist Leo Baekeland (1863-1944).
One of the primary motivations for developing plastic was the bur-
geoning electronics industry of the late 19th century. Electrical engi-
neers needed a flexible material that was not an electrical conductor,
with which they could protect and insulate electrical wires and circuits.
Chemists had been experimenting with materials such as phenol and
formaldehyde for decades before Baekeland hit upon the right combi-
nation of these substances, as well as the right temperature and pressure
at which they would combine to form a useable plastic.
Since the development of Bakelite, many other types of plastic have
appeared. Plastics have a huge number of applications today, including
bags and containers of all shapes and varieties.
Materials called composites are also in widespread use. A composite
consists of small fibers of one substance embedded in a matrix of an-
other substance. The fibers reinforce the matrix, adding stiffness. One of
the first composites was fiberglass, in which thin fibers of glass reinforce
a plastic material. Fiberglass is strong yet light in weight.
Composites fill many needs, especially the need for tough, light-
weight materials used in cars and airplanes. Vehicles of the past have