Basic Technology of Plastics - Introduction to Polymeric Composites with Rice Hulls - page 11

2 Basic Technology of Plastics
2.1 Introduction to Plastics
' Plastic ' comes from the Greek word plastikos , which means a material that can be
shaped by heat and pressure. A more sophisticated definition may be: a large and
varied group of materials consisting wholly or in part of combinations of carbon
with oxygen, nitrogen, hydrogen and other organic or inorganic elements which,
while solid in the finished state is made liquid and thus capable of being formed into
various shapes, most usually through the application (either singly or together) of
heat or pressure.
Plastics are made from polymers and are, in general, available in the form of liquids,
powders, and pellets. ' Polymer ' is derived from the Greek words, poly (meaning
many) and meros (meaning a basic unit or part). Polymers are also known as 'resins'
(incorrect but widely used) or 'macromolecules' from the Greek word macros
(meaning long elastomers (which are polymers that can be stretched by >200% of
their original length)). According to American Standards for Testing Methods, an
elastomer is a polymeric material that at room temperature can be stretched at least
twice its original length and, upon immediate release of stress, will return quickly to
approximately its original length.
Plastics are considered 'wonder' materials and have replaced many traditional
materials in all spheres of human activity. They have been used for a long time
and have seen rapid growth in terms of quality and consumption. With research and
development continuing in polymers and plastic resins, applications are spreading
from traditional domestic and industrial uses to those in automobile and even to
space travel.
2.2 Chemistry of Plastics
Instead of highly technical and theoretical chemistry, the basics of the chemistry
of plastics are described here in a simple and practical manner to help the reader
understand polymeric materials relevant to this topic.