Plastics have come of age over the last 40 years. The material has evolved from
a synthetic "substitute" for other materials to a valuable new raw material. It
now occupies a permanent place in out technology and may be the basic material
of the future.
This primer is designed to familiarize you with the possibilities of plastics;
most particularly acrylics.
Two hundred years ago, when the pioneers and early settlers were building
shelters and towns, they used to use the material resources of the land; as
structural materials, as furniture, and as ornamentation to what they built.
They chose their materials carefully with an eye to the purpose the finished
product would serve. Wood, for instance, came in different strengths and
hardness. Some stone could be quarried and cut more easily than others. Various
metals were formed for different purposes. These early builders and craftsmen
learned which type of available raw materials would be most suitable for
specific tasks. Technology has come of age, and now we have access to materials
offering a variety of use beyond those basic needs of shelter, furniture and
decoration. One of the most important of these materials is plastic, and
plastic is what this primer is all about.
If we take a look at the definition of the word plastic, it can help us to
understand what is so exciting and unique about this material. One finds the
term used in an artistic sense as sculptural and characterized by modeling or
molding of the surfaces. Therefore, an object of art could be described as
being plastic or as having a great deal of plasticity. Webster ties the word
plastic to the creative forces in nature and the adaptability of animals in
their environment. Looking to the Greek root of the word plastic, plastikos, we
find the definition as being to mold or form something. You will agree then
that the word plastic is an ideal word for describing this valuable material
that has found permanent home in our lives.
There are two basic kinds of plastics: Thermoset, which, when formed, remain in
the formed shape and cannot revert to a liquid state, the final shape is set
during the manufacturing phase, and thermoplastics which, when heated to
forming temperatures, are pliable and can be reshaped.
Examples of thermoset plastics can be found in your home, in your car, even in
some of the sporting goods you use. One of the earliest plastics discovered and
put into commercial service were phenolic resins. This was a material which
could take not only heavy impact, but was both heat and chemically resistant.
Modern day usage of phenolics can be seen in the PC boards of your solid state
TV, the handle of your buck knife, as well as your coffee pot, and even the
pulleys and cleats of your racing yacht.
The use of thermoplastics is by far the leader in today's industrial society.
The packaging industry requires more plastics at an ever increasing rate. Take
another look at that soft drink bottle next time you pour from it.
Thermoplastics are playing an important part in saving energy for America.
Plexiglass storm windows have been in service for several decades and new
glazing materials like Twinwall sheets are giving its users insulation benefits
of up to 40% better thermal retention than plate glass alone. Plastics will
enhance the beauty of our future automobiles while shaving off hundreds of
pounds of excess weight per car. In the model year 1979, Detroit has used
nearly one million tons of combined types of plastics in their efforts to reach
these energy goals.
So we find that acrylics fall into the thermoplastics category, which means
they can be formed when heated to the proper temperature. Their chemical
composition is that of a clear, water-white, transparent liquid substance of
monomer that can be polymerized into sheets, rods, tubes, molding pellets and
additives. Additives are primarily used in the production of other materials,
e.g., multi-grade oils, other plastics, paints, and floor polishes. So think of
acrylics as a new "raw" material. A material as basically important as the
traditional resources of wood, metal stone, etc.
Acrylic is a derivative of natural gas: see chart below.
(Natural Gas)-->>(Propane) -->>(Propylene)-->>(Isopropyl Alcohol) -->>(Acetone)
+ hydrogen cyanide -->>(Acetone Cyanohydrin)
+ sulfuric acid -->>(Methacrylamide)
+ methanol -->>(Methyl Methacrylate)-->> (Acrylic Plastic) Plexiglass, Lucite, Perspex, and Acrylite!
