Polymers, synthetic & bio polymers, synthesis, formulation and applications

Polymers are closely related to our lives, and can be found everywhere. Almost every
household utilize verity of polymers daily. For example, most of the bottles containing
drinks, cooking oils, cleaning liquids are made from polymers. Most of the clothing
including fabric, dresses, shirts, shoes, slippers, and fashion jewelry, toys, carpets,
draperies, and the list could go on and on. Thus, the polymer related products has a
vital part in essential items we used in day today life

Polymer basics:

Synthetic polymer: Man made polymers which are not
naturally occurring polymeric materials

Plastics: depending on the elastic modulus and
elongation some polymers are called plastics. i.e.
elastomers or fibers are not referred to as plastic

Elastomer: Polymeric materials that comes back to its
original shape after removing a deforming force (e.g.
natural rubber)

Fibers: man made (synthetic) or naturally occurring
fibrous-shaped (filaments) polymers (e.g. cotton fibers)

Thermoplastic: the polymeric materials that can be
deformed reversibly between its melting and degradation
temperatures, If not it would be a thermoset.

History of Polymers:

A polymer consists of molecules with large molecular mass
which was build by repeatedly covalently attaching small
structural units called monomers. The term was derived
from the Greek words polys and meros which means many
and parts respectively. The term Polymer came into use in
1833 at the same time with Henri Braconnot's discovery of
nonflammable material by reacting nitric acid with cellulose
in wood or cotton. This is considered as the first man-made
polymeric material.

With this work, two kinds of polymer materials became
available, namely natural and synthetic. The main building
block for plants, cellulose; major building materials of
animals, protein; the elastic polymer that find in the sap of
various plants, rubber; a viscous gum found in cell walls of
brown algae, alginate; a long chain polysaccharide found in
the exoskeleton of shrimps, lobsters, ants, beetles, chitin;
are some of the known natural polymers. Among these
various different natural polymers, materials known amber
and Shellac are known to be used for various applications
for centuries.

Amber, which is also known as the fossil resin is found in
the world in the range of 30 - 90 millions old. Amber usually
made from several precursors, and over the time several
reaction mechanisms occur to make the hard resin. Due to
its inherent beauty, amber is widely used in making
ornamental objects. Sometimes, millions of years old small
insects, leaves, tree frogs etc, are found trapped and well
preserved in amber which is very well worth to scientists.

Shellac is a material secreted by the female lac insect
(Coccus lacca) mainly found in Thailand and Assam. The
secretion harvested on bark of the trees is collected and
purified to get the natural plastic which can be molded
into various articles by heat and pressure methods.
There is evidence for using polymers in the form of animal
skins for clothing, shoes, and as shelter as early as
about 10,000 B.C. and by about 5000 B.C., various
natural polymeric fibers were used for making apparel and
rope etc.

The impetus for manufacturing synthetic fibers for textiles
came through observing the silkworm making silk
filaments by turning their protein derived thick-sticky
liquid into solid filaments. By imitating this method, more
often fibers are manufactured by converting the solid
polymer into a sticky liquid and forcing it through holes in
a spinneret in streams and turning to a solid filament.
Inspired by the study of silk filament production by
caterpillars, a group of organic chemists led by Dr. W. H.
Carothers, carried out highly significant work in finding
small molecules that would react to give long chain
polymeric molecules. Their research has led to invent the
first synthetic textile fiber, Nylon. This is still in the fore
front of useful fibers and is used extensively in textiles,
carpets, hair and tooth brushes and many other
applications.

Polymers and the environment:

Polymers are widely known as plastics among people.
However, the big image on plastics for the most is not a
positive one, probably due to some of the environmental
issues that cased by various polymers. It should be noted
that not all polymers have a negative environmental
impact. Thus, it would be better to have a general
understanding of polymers, their uses, advantages and
disadvantages, and the modifications that are possible to
improve the properties of the polymers for the better.