• POLYMER MATERIALS
• CLASSIFICATION OF POLYMER
• STRUCTURE OF LONG CHAIN POLYMERS
• CRYSTAL OF LONG CHAIN POLYMER
• Polymer are long chain giant organic
molecules assembled from many small
molecules called monomers .
• More monomer molecules joined in units of
The polymers are a diverse group of
They are the main components of plastics,
rubbers, resins, adhesives and paints.
These materials have distinctive
microstructures built from macromolecular
chains and networks of carbon and other
CLASSIFICATIONS OF POLYMERS
Long chain Polymers
• A type of plastic that can be softened by
heat, hardened by cooling, and then
softened by heat over and over again.
Thermoplastics are not cross-linked.
• Thermoplastics such as polyethylene,
Nylon, Polyvinyl chloride which soften on
Clothing and furniture
chloride (uPVC) for
of dialysis installations and
temporary blood storage
covering the home,
hospitals, offices, schools,
thermoset - having the property of becoming permanently
hard and rigid when heated or cured; "the phenol resins and
plastics were the original synthetic thermosetting materials"
They are hard and rigid at room temperature and do not soften
Examples and uses of thermoset plastic materials:
Epoxy resins - used as coating materials, caulks, manufacture of
insulating materials, etc ...
Phenolic resins - tool handles, billiard balls, sprockets,
insulation, etc ...
Unsaturated polyester resins - manufacture of plastics
reinforced fiberglass commonly known as polyester,
fillers, etc ...
The definition of a natural polymer is a
polymer that results from only raw materials
that are found in nature. Some of these
natural polymers include DNA and RNA. These
are critical in genes and life processes.
Cotton, DNA ,wool, wood etc. are some of
the naturally occurring polymers.
Homopolymers- consist of chains with identical
bonding linkages to each monomer unit. This
usually implies that the polymer is made from
all identical monomer molecules.
These may be represented as : -[A-A-A-A-A-A]-
A polymer of two or more different
monomers. The synthetic rubber used to
make tire treads and shoe soles, for example,
is a copolymer made of the monomers
butadiene and styrene
These may be represented as : -[A-B-A-B-A-B]-
STRUCTURE OF LONG CHAIN
A very long strand of repeating molecules
linked together by primary bonds. Polymer
chains orient themselves in lines as they enter
a mold, but may be annealed so they can
Properties of Polymers
The physical properties of a polymer, such as its strength
and flexibility depend on:
• Chain length - in general, the longer the chains the stronger
• Side groups - polar side groups give stronger attraction
between polymer chains, making the polymer stronger;
• Branching - straight, un branched chains can pack together
more closely than highly branched chains, giving polymers
that are more crystalline and therefore stronger;
• Cross-linking - if polymer chains are linked together
extensively by covalent bonds, the polymer is harder and
more difficult to melt.
Characteristics of Polymers
Low coefficient of friction.
Good corrosion resistance.
Good mould ability.
Excellent surface finish can be obtained.
Can be produced with close dimensional tolerances.
Poor tensile strength.
Low mechanical properties.
Poor temperature resistance.
Can be produced transparent or in different colours
Applications of Polymers
Polymeric materials are used in and on soil to
improve aeration, provide mulch, and promote plant
growth and health.
Many biomaterials, especially heart valve
replacements and blood vessels, are made of polymers
like Dacron, Teflon and polyurethane.
Plastic containers of all shapes and sizes are light
weight and economically less expensive than the more
traditional containers. Clothing, floor coverings,
garbage disposal bags, and packaging are other polymer
Automobile parts, windshields for fighter
planes, pipes, tanks, packing materials,
insulation, wood substitutes, adhesives, matrix
for composites, and elastomers are all polymer
applications used in the industrial market.
Playground equipment, various balls, golf
clubs, swimming pools, and protective helmets
are often produced from polymers.