This document provides an overview of polymers including their classification, polymerization processes, characteristics, processing techniques, and applications. Polymers are large molecules formed by linking repeating small molecule units called monomers. They can be classified based on their source, structure, type of polymerization, or molecular forces. The two main types of polymerization are addition and condensation. Polymers have properties like low density, corrosion resistance, and moldability. Common processing methods are blow molding, injection molding, and extrusion. Polymers have a wide range of applications in consumer goods, industry, sports, and medicine.

1. -:POLYMERs:-

2. -:Contents:-
1. Introduction
2. Classification of polymer
3. polymerization
4. Characteristics of polymers
5. Polymer Processing Techniques
6. Applications of polymers

3. INTRODUCTION
• A word polymer is a combination of two Greek words, “Poly” means
“many” and “Mers” meaning “parts or units”.
• A polymer is a large molecule formed by repeated linking of the
small molecules called “monomers”.
• More monomer molecules joined in units of long polymer.

4. INTRODUCTION
• Another common name for many synthetic polymers is plastic.
• which comes from the Greek word "plastikos",
• Means suitable for molding or shaping.
• Many objects in daily use from packing, wrapping, and building
materials are made of polymers. For example:

6. CLASSIFICATION OF POLYMER
• CLASSIFICATION based on SOURCE
• CLASSIFICATION based on STRUCTURE
• CLASSIFICATION based on POLYMERISATION
• CLASSIFICATION based on MOLECULER FORCE/
temperature

7. Classification based on source
• Natural polymers:-
a polymer that is in its pure natural form is known as natural polymer.
Example:- Proteins, Cellulose, Starch, Rubber.

8. Classification based on source
• Synthetic polymers:-
A polymer that is derived from natural polymers is known as synthetic
polymer.
Example: nylon, PVC, pe, pp, polystyrene

9. PVC LDPE BAKELITE
Classification based on structure

10. classification based on moleculer force
• thermoplastic polymers:-
• These are linear or slightly branched long chain polymers.
• which can be softened on heating & reversibly hardened on cooling repeatedly.
• Their hardness is a temporary property & varies with temperature.
• Can be recycled.
Example:- polyvinyl chloride.

11. classification based on moleculer force
• Thermosetting polymers:-
• long chains of molecules that are strongly cross linked to each other to form a
network.
• It doesn't melt upon heating but begins to decompose.
• Cant be recycled.
Example: bakelite

12. comparison

13. polymerization
• The process of converting a monomer or mixture of monomers in to Polymer is
known as Polymerization.
• There are two main ways to conduct polymerization:
1. Addition polymerization
2. Condensation polymerization

14. Types of polymerization
• Addition polymerization:-
 the polymer is formed from the monomer, without the loss of any material, and
the product is the exact multiple of the original monomeric molecule.
 Addition polymerization proceeds by the initial formation of some reactive species
such as free radicals or ions.
 It is also called chain growth polymerization.
 Polymers formed by this is also known as addition polymer.

15. This process involves three steps:-
a) Chain initiation step - addition of phenyl free radical formed by the peroxide to the ethene double
bond ,thereby forming a larger radical.
b) Chain propagation step - repetition of this sequence with new and bigger radicals.
c) Chain terminating step - the product radical thus formed reacts with another radical to form the
polymerized product.

16. Types of polymerization
• Condensationpolymerization:
• process in which two monomers react to form a larger molecule and eliminate a smaller
molecule (usually water, ammonia, methanol or hydrogen chloride).
• it also called as step-growth polymerization.
• Polymer formed from this is also known as condensation polymer.
Example:-
polyester = dimethyl terephthalate +ethylene glycol

17. Characteristics of polymer
 Low Density.
 Low coefficient of friction.
 Good corrosion resistance.
 Good mould ability.
 Excellent surface finish can be obtained.
 Can be produced with close dimensional tolerances.
 Economical.
 Poor tensile strength.
 Low mechanical properties.
 Poor temperature resistance.
 Can be produced transparent or in different colours

18. Polymer Processing techniques
• Methods used to form polymers into different types of
products/Shapes are:
1. Blow Molding
2. Compression Molding
3. Injection Molding
4. Extrusion
5. Casting

23. Application of polymers
1. ConsumerScience :-
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 applications.

24. Application of polymers
• Industry:-
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.

25. Application of polymers
• Sports:-
Playground equipment, various balls, golf clubs, swimming pools, and
protective helmets are often produced from polymers.

26. Application of polymers
• Medicine:-
Many biomaterials, especially heart valve replacements and blood vessels,
are made of polymers like Dacron, Teflon and polyurethane.