Polymer chemistry involves the study of polymers, which are large molecules composed of many repeating structural units connected by covalent bonds. The monomers that make up polymers are linked through polymerization reactions. Polymers can be classified based on their structure, source, number of monomers, arrangement of monomers, and configuration. Common types of polymers include linear, branched, and cross-linked polymers. Polymers are also classified as natural, semi-synthetic, or synthetic based on their source. Polymerization reactions are either addition polymerization, involving chain growth, or condensation polymerization, involving step growth. Polymers have a variety of applications and properties depending on their structure and bonding forces.

1. WELCOME TO
POLYMER CHEMISTRY
Submitted by:
Mohammad Ahmad,Naresh Kumar

2. Introduction:
 The word “Polymer” is derived from two Greek
words , Poly(Many) and meros (Parts or units). A
polymer is a large molecule formed by combining
small molecules. The individual small molecules
from which the polymer is formed are known as
“Monomers” and the process by which the
monomer molecule are linked to form big
molecule is called “Polymerization”.
𝑛𝐶𝐻2=𝐶𝐻2 (𝐶𝐻2-𝐶𝐻2)
Polymerizati
on n
Ethylene
(Monomer)
Polyethylen
e
(Polymer)

3. What is a polymer ?
 It is geometrically a long chain coil, represented by figure given
below.
 Chemically, it’s a macromolecule represented as , which is
actually a very long chain macromolecule, constituted by
several number of a particular chemical unit often called repeat
unit.
Fig: 1.1

4.  Structurally its represented as [ MU ] , where MU is
known as repeat unit and n is known as degree of
polymerization.
 The overage number of repeated unit attached with a single
polymer chain is known as “Degree of Polymerization”, and it
is represented by 𝑋 𝑛. 𝑋 𝑛 is the number average degree of
polymerization and is given by:
𝑋 𝑛=
𝑖=1
∝
𝑥 𝑖 𝑁 𝑖
𝑖=1
∝ 𝑁 𝑖
DEGREE OF POLYMERIZATION:
n

5. Classification of Polymers:
BasedonStructure:
• In these polymers monomers are linked with each other and
form a long straight chain.
• These chains has no any side chains. Ex. Polyethene, PVC,
Nylons, polyesters etc.
• Their molecules are closely packed and have high density,
tensile strength, and
• melting point.
Linear Polymer
• They have a straight long chain with different side chains.
• Their molecules are irregularly packed hence they have low
density, tensile strength and melting point.
• Ex. polypropylene (side chain —CH3), amylopectin and
glycogen.
Branched Polymer
•In these monomeric units are linked together to
constitute a three dimensional network.
•The links involved are called cross links.
•They are hard, rigid .and brittle due to their network
structure. Ex. Bakelite, melamine, formaldehyde
resins, vulcanised rubber etc.
Cross-Linked Polymer

6. Classification on the basis of source:
Polymers either
obtained from plants
or animal are called
natural polymers.
They are called plant
and animal
polymers.
Ex. Cellulose, Jute,
Lichen, Silk, Wool,
Leather, RNA, DNA,
Natural rubber.
The polymers
obtained by simple
chemical treatment
of natural fibers to
improve their
physical properties
like lastrus nature,
tensile strength are
called semisynthetic
fibers.
Ex. Acetate rayon,
cuprammonium silk,
viscous rayon.
The fibres obtained
by polymerization of
simple chemical
molecules in
laboratory are
synthetic fibres.
Ex. Nylon, erylene,
polyethene,
polystyrene,
synthetic rubber,
nylon, PVC, backlite,
Teflon, Orion etc.
Natural Polymer
Semi-synthetic
Polymer
Synthetic Polymer

7. Based on number of monomer:
Polymer is made from all
identical monomer
molecules e.g., Polyethylene,
Polystyrene,
Polyvinylchloride etc.
Polymer made from two
different type of monomer
units e.g.. Styrene butadiene
rubber, Styrene acrylonitrile
rubber etc.

8. Based on the arrangement of monomers within the chain:
Random
Copolymer
• Random copolymer contains a random arrangement of
the monomers. E.g. ABCBCBABCBCACBABCBCAC
Alternating
Copolymer
• Alternating copolymer contains a alternate arrangement
of the monomer. E.g. ABABABABABABABABA
Block
Copolymer
• Block copolymer contains blocks of monomers of the
same type. E.g. AAAAAAABBBBBBBA
Graft
Copolymer
•Contains a main chain polymer consisting of one type of monomer
with branches made up of other monomers. E.g. AAAAAAAA
B
B
B
B

9. Based on Configuration:BASEDON
CONFIGURATION
Isotactic polymer: The head-to-tail configuration, in which functional
groups all on the same side of the chain, is called isotactic polymer. E.g.,
Atatic polymer: The arrangement of functional groups are random
around the main chain, it is called atatic polymer. E.g.,
Syndiotactic: The arrangement of the side groups is in alternating
fashion, it is called syndiotactic polymer. E.g.,
C C
H
H
H
R R
H
H
H
CC
R
H
H
H
CC
R
H
H
H
CC
C C
H
H
H
R R
H
H
H
CC
R
H
H
H
CC
R
H
H
H
CC
C C
H
H
H
R
C C
H
H
H
R
C C
H
H
H
R R
H
H
H
CC

10. forces:
Elastomers: These are rubber like solids with
elastic properties. In these elastomeric polymers, the
polymer chains are held together by the weakest
intermolecular forces. E.g. Buna-S, Buna-N, Neoprene,
etc.
Fibres: Fibres are the thread forming solids which
possess high tensile strength and high modulus. These
characteristics can be attributed to the strong
intermolecular forces like hydrogen bonding. E.g.
Polyamides(nylon 6,6), Polyesters(terylene), etc.
Thermoplastic polymers: These polymers
possess intermolecular forces of attraction intermediate
between elastomers and fibres. E.g. Polythene, Polystyrene,
Polyvinyls, etc.
Thermosetting polymers: These polymers are
cross-linked or heavily branched molecules, which on
heating undergo extensive cross-linking in moulds and
again become infusible. These cannot be reused. E.g. Urea-
Formaldehyde resins, Bakelite, etc.

11. Types of Polymerization
Reaction:
 There are two broad polymerization reaction.
Condensation
Polymerization or
Step Growth
Polymerization.
Addition
Polymerization or
Chain Growth
Polymerization.

12. Addition Polymerization or Chain
Growth Polymerization.
 In these type of polymerization, the molecule of the same monomer or different
monomer add together on a large to form a polymer. The monomers used are
unsituated compounds. E.g. alkenes, alkadines and their derivatives. This mode of
polymerization leading to an increase in chain growth or chain length can take place
through the formation of either free radicals or ionic species. However, the free
radicals the governed addition or chain growth polymerization is the most common
mode.
 Free Radical mechanism:
A variety of alkenes or dines and their derivatives are polymerized in the presence
of a free radical generating initiator(catalyst) like benzoyl peroxide, acetyl
peroxide, tert-butyl peroxide, etc. for example, the polymerization of ethene to
polythene consists of heating or exposing to light a mixture of ethene with a small
amount of benzoyl peroxide initiator. The process starts with the addition of phenyl
free radical formed by the peroxide to the ethene double bond thus generating a new
and larger free radical. This step is a called chain-initiating step. As this radical reacts
with another molecules of ethene, another bigger sized radical is formed. The
repetition of this sequence with new and bigger radicals carries the reaction forward
and the step is termed as chain-propagating step. Ultimately, at some stage the
product radical thus formed reacts with another radical to form the polymerized
product. This step is called the chain-terminating step. The sequence of steps may be
depicted as follows:

13.  Chain initiation steps:
𝐶6 𝐻5 − 𝐶 − 0 − 0 − 𝐶 − 𝐶6 𝐻5 → 𝐶6 𝐻5 − 𝐶 − 0 → 2 𝐶6 𝐻5
𝐶6 𝐻5 + 𝐶𝐻2 = 𝐶𝐻2 → 𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2
 Chain propagating steps:
𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2 + 𝐶𝐻2 = 𝐶𝐻2 → 𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2
𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2
 Chain terminating steps:
𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2
+ 𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶6 𝐻5
𝐶6 𝐻5 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2 − 𝐶𝐻2
OOO
n
Benzoyl Peroxide
Phenyl Radical
Polythene
n
n
n n

14. Some Common Addition Polymers

15. CONDENSATION POLYMERIZATION OR
STEP GROWTH POLYMERIZATION.
 This type of polymerization generally involves a repetition
condensation reaction between two bi-functional monomers. These
polycondensation reactions may result in the loss of some simple
molecules as water, alcohol, etc., and lead to the formation of high
molecular mass condensation polymers.
 In these reactions, the product of each step is again a bi-functional
species and the sequence of condensation goes on. Since, each step
produces a distinct functionalized species and is independent of
each other, this process is also called as step growth polymerization.
 The formation of terylene or Dacron by the interaction of ethylene
glycol and terephthalic acid is an example of this type of
polymerization.
𝑛𝐻𝑂𝐻2 𝐶 − 𝐶𝐻2 𝑂𝐻 + 𝑛𝐻𝑂𝑂𝐶 − −𝐶𝑂𝑂𝐻 → 𝑂𝐶𝐻2 − 𝐶𝐻2 − 𝐶 − − 𝐶
n
0 0Ethylene glycol
(Ethane- 1,2-
diol)
Terephtahlic acid
(Benzene-1,4-
dicarboxylic acid)
Terylene or dacron

16. SOME CONDENSATION POLYMERS

17. Thermoplastic polymers differ from thermosetting polymers
(Bakelite, vulcanized rubber) since thermoplastics can be
remelted and remolded.
Thermosetting plastics when heated, will chemically
decompose, so they can not be recycled. Yet, once a thermoset is
cured it tends to be stronger than a thermoplastic.
Typically, linear polymers with minor branched structures (and
flexible chains) are thermoplastics. The networked structures
are thermosets.
17
THERMOPLASTICS AND THERMOSETS POLYMERS:

18.  Polymer degradation is a change in the properties—tensile strength, color, shape, etc.—of a
polymer or polymer-based product under the influence of one or more environmental factors
such as heat, light or chemicals such as acids, alkalis and some salts. These changes are usually
undesirable, such as cracking and chemical disintegration of products or, more rarely,
desirable, as in biodegradation, or deliberately lowering the molecular weight of a polymer for
recycling. The changes in properties are often termed "aging".
 Degradation can be useful for recycling/reusing the polymer waste to prevent or reduce
environmental pollution. Degradation can also be induced deliberately to assist structure
determination.
 Polymeric molecules are very large (on the molecular scale), and their unique and useful
properties are mainly a result of their size. Any loss in chain length lowers tensile strength and
is a primary cause of premature cracking.
Degradation of Polymer:

19. Conducting
Polymers
Intrinsically
Extrinsically
Coordination
Doped

20. CONDUCTING Polymers:
 Polymeric materials has been synthesized which possess
electrical conductivities on par with metallic conductors.
Such polymers are called conducting polymers.
 Different types of conducting polymers are discussed below:
I. Intrinsically conducting Polymers:It’s a polymer whose backbones or
associated groups consist of delocalized electron-pair or residual charge. Such
polymers essentially contain conjugated 𝜋-electrons backbone, which is responsible
for electric charge. In an electric field, conjugated 𝜋-electrons of the polymer get
excited, thereby can be through the solid polymeric material. Overlapping of orbitals
over the entire backbone results in the formation of valence bands as well as
conduction bands, which extends over the entire polymer molecule.
 Important commercially produced conducting polymers:
a) Polyacetylene polymers e.g., poly-p-phenylene, poly-m-phyenylene sulphide, etc.
b) With condensed aromatic rings, e.g., polyaniline, polyanthrylene, etc.
c) With aromatic heteroaromatic and conjugated aliphatic units, e.g., polythiophene,
 polypyrrole, polybutadienylene, etc.

22. It is a resin or
polymer filled with
conducting elements
such as carbon black,
metallic fibres ,
metal oxides, etc.
It’s a product obtained
by blending a
convectional polymer
with a conducting
polymer either by
physical or chemically
change.
Conductiveelement-filledpolymer
Blendedconductingpolymer
III. Extrinsically conducting polymers are those polymers whose
conductivity is due to the presence of “externally” added ingredient in
them. These are following two types:

24. Biopolymers:
Nucleic acid polymers (DNA, RNA)
Amino acids polymers (Proteins)
Sugar polymers (Carbohydrates)
Lipids

25. Nuclei acid polymer:
 Nucleic acids are polynucleotides(a nucleotide consist of a sugar, a phosphate
group and a nitrogen base residue). Thus, nuclei acids are high polymers of
nucleotide. In other words, nucleotides are the repeating of nuclei acids.
Types of nuclei acids: Depending upon the type of sugar residues, there are two
types of nuclei acids:
1. DNA(or deoxyribonucleic acid): It’s a polynucleotide consisting of:
(i) deoxyribose (a pentose) as the sugar, and
(ii) adenine, guanine, cytosine or thymine as the base in its structure. It’s a ‘master
molecule’
contained in the chromosomes of the nucleus of a cell. It is responsible for the
inheritance
of genetic character of a particular species of a living cell.

26. 26
The monomers:
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
Phosphate-
Sugar (backbone) of
DNA

27. 2. RNA( ribonucleic acid)
It is ribonucleic acid, formed in the nucleus and is found in the cytoplasm of the cell:
Types of RNA:
1. Ribosomal-RNA (or r-RNA) is found in the ribosomes; and it is, usually, associated with proteins to
form the ribosomes. It is synthesized in the nucleus by DNA. It is single-stranded, comprising about
80% of the RNA. It is metabolically stable.
Functions:
i. This forms the site for protein synthesis.
ii. It is also supposed to help the binding of m-RNA to the ribosomes, during protein synthesis.
2. Messenger-RNA(or m-RNA) carries the genetic message(code) from
the DNA to ribosomes. It is produced by the DNA. m-RNA is also single-
stranded; and constitutes about 15% of total RNA.
Functions:
It carries the genetic information from DNA to the ribosomes, where protein is synthesized.
3. Transfer-RNA (or t-RNA) is synthesized in the nucleus by the DNA. It is also called soluble-RNA. It is
single-stranded. There are 20 different kinds of t-RNA; and each type has a specificity for a particular
amino acid. It constitutes about 5% of total RNA. It has very short life.
Functions:
It acts as ‘carriers’ of amino acids, i.e., it carries amino acids from different parts of cytoplasm to the
ribosomes, during protein synthesis.

28. 28
Phosphate-
sugar
backbone
holds the DNA
macromolecule
together

29. LIPIDS
• Lipids are the hetrogeneous group of organic
compound,which are the essential consitituents of all
plant and animal cells.
• BASIC CONSITITUENT OF LIPIDS:
• Lipids are composed of carbon hydrogen and oxygen and ocasionally
nitrogen and phosphorous.
• CLASSIFICATION OF LIPIDS:
• FATS AND OIL
• WAXES
• PHOSPHOLIPIDS
• GLYCOLIPIDS
• STEROIDS

30. CARBOHYDRATES
 Carbohydrate are agroup of compounds
represented by the general formula CX(H2O)Y.
 CARBOHYDRATE ARE DIVIDED INTO GENERALLY
THREE PARTS:
 MONOSACCHARIDES- Monosaccharides are the
simplest carbohydrates which cannot be hydrolysed to
smaller molecules.
 Eg- Ribose (C5H10O5) , Glucose (C6H12 O6) etc
 OLIGOSACCHARIDS- yield 2 to 9 monosaccharides
molecule on hydrolysis.
 Eg- Maltose---- 2 Glucose
Sucrose---- Glucose + Fructose

31. POLYSACCHARIDES
 They are biopolymers in which monosaccharides form
the structure monomeric units.
 Eg- Starch Cellulose Glycogen etc
 These on hydrolysis yield monosaccharides only and
their general formula is C6H10O5
 FUNCTION OF CARBOHYDRATES:
 They form structural components of cell.
 Some carbohydrates act as food. Eg- Canesugar ,
Glucose and starch.
 They act as storaof chemical energy in the form of
glucogen in liver.
 Cellulose present in grass and plants act as a food for
various grazing animals.

32. PROTEINS
 Protein are polymeric amides composed of long chain of numerous
amino acid.
 IMPORTANCE OR USES OF PROTEIN:
Proteins among the most important type of substance present in living
Cell. They are found in all cells of living organism. Basically protein are
ranked first amongst the bio molecules.
ROLE OF PROTEIN:
 They serve as a fuel to yield energy.
 They serve as the structural components of the living organism.
 They take part in genetics.
 They help in maintainence of fluid valance.

33. Introduction to Polymeric
Composites.
• A composite is a structural material
that consists of two or more combined
constituents that are combined at a
macroscopic level and are not soluble
in each other.
• Reinforcing phase: fibers, particles, or
flakes
• Matrix phase: polymers, metals,
ceramics

34. Characteristics of Composite
Materials:
• High specific strength and modulus, as well as high
fatigue strength and fatigue damage tolerance.
• Anisotropic.
• Designable or tailorable materials for both
microstructure and properties.
• Production of both material and structure or
component in a single operation - manufacturing
flexible, net-shape, complex geometry.
• Corrosion resistance and durable.
• Other unique functional properties - damping, low
CTE (coefficient of thermal expansion).

35. Types of Composite
Materials:
• Particulate composites
• Flake composites
• Fiber composites
• Nano composites

36. USES OF POLYMER IN OUR DAILY LIFE
• polymers used are plastics
paints,adhesives,lubricants,rubber etc.
• synthetic polymers play a vital role in
our life. for eg., the materials used in
day-today life like buckets,
switches,dresses etc.
• In mfg of bottles, syringes, vials,
cathaters, and also in drug
formulations.

37. POLYMERS CAN BE

39. Thank
you for
your
Attenti
on