Polymer science revolves around the study of macromolecules known as polymers, which are formed by linking together repeating units called monomers. Understanding the relationship between polymers and monomers is fundamental to grasping the diverse properties and applications of these materials. Additionally, we'll delve into the nomenclature of polymers, which involves the systematic naming conventions used to describe their structure and composition. Clear and standardized nomenclature ensures effective communication within the scientific community and facilitates the classification of polymers based on their chemical structure, properties, and applications.

2. • Polymers are widely used advanced materials, which are found almost in
every material used in our daily life. The very existence of life is
virtually the formation, transformation and decomposition of the
polymers. This includes carbohydrates, proteins and nucleic acid in our
bodies.
• Fibers in clothing; soil where food is grown; protein and starch we eat;
elastomers in automobile tyres, paints, plastic wall, floor coverings, foam
insulation, dishes, furniture, pipes etc are also polymeric. In-spite of the
many varieties like fibers, elastomers and plastic, they all have a similar
structure and are governed by same theories.

3. DNA Rubber Cellulose Nylon
Polyester Wool Teflon Epoxy

4. • The word polymer is derived from the Greek words “poly” and “meros”
meaning many and parts respectively. Thus polymers or macromolecules
are giant molecules made up of multiple repeating units which are joined
together by covalent bonds. They have molecular weights at least 100
times greater than those of smaller molecules such as water or methanol.
• Examples:
PVC(polyvinylChloride), Poly(methylmethacrylate), Nylon -6, Nylon -6,6,
Polyurethanes, Polyoxyethylene, Natural rubber, Orlon – PAN, Dacron –
PET, etc.

5. • Monomer is the basic building unit which repeats
itself to form a polymer.
• Examples:
Ethylene, vinylchloride, styrene, isoprene, chloroprene
(2-chlorobuta-1,3-diene),tetrafluoroethylene,
acrylonitrile, etc.

6. • Degree of polymerization is defined as the number of repeating
monomeric units in a polymer.
• Degree of polymerization of:
(i) = 1000
(ii) = 50000
𝐷𝑒𝑔𝑟𝑒𝑒 𝑜𝑓 𝑝𝑜𝑙𝑦𝑚𝑒𝑟𝑖𝑧𝑎𝑡𝑖𝑜𝑛 =
𝑀𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑜𝑙𝑦𝑚𝑒𝑟𝑖𝑐 𝑛𝑒𝑡𝑤𝑜𝑟𝑘
𝑀𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑡ℎ𝑒 𝑟𝑒𝑝𝑒𝑎𝑡𝑖𝑛𝑔 𝑢𝑛𝑖𝑡
(If DP = 1 then it is monomer; DP=2 dimer; DP = 3 trimer; DP = 4
tetramer).

7. • Polymers with low degree of polymerization are known as oligo polymers
and their molecular weight ranges from 500 - 5000.
• Many oils are oligomeric, such as liquid paraffin. Plasticizers are
oligomeric esters widely used to soften thermoplastics such as PVC.
Polybutene is an oligomeric oil used to make putty.
• Polymers with high degree of polymerization are known as high polymers
and their molecular weight ranges from 10,000 - 2, 00,000.

8. Little rhyme or reason is associated with the common names of
polymers.
• Some names are derived from the origin of the material (Example :
Hevea brasilliensis (natural rubber) – meaning rubber plant from Brazil).
• Some named after the discoverer (Example : bakelite – discoverer Leo
Baekeland).
• Some named according to the number of carbons used in their
synthesis (Examples : nylon group – Nylon 6, 10; Nylon -6,6; Nylon -6).

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• Some names are source based i.e they are based on the common name
of the reactant monomer, preceded by the prefix “POLY”.
(Examples:Poly(methylmethacrylate);Polystyrenepolypropylene;poly-
acrylonitrile;polyvinylchloride; polytetrafluoroethylene).
• Some names are structure based (employed for simple polymers and
the IUPAC system is used). (Example: Poly(1 chloroethylene)).
• Many polymer families are referred to by the name of the particular
linkage that connects the polymers. (Examples : Polyamide;
Polyurethanes).

10. Continue....
• Trade names and abbreviations are also used to describe the
materials.(Examples : Orlon –PAN; Dacron – PET).
Functionality is the number of reactive sites or number of bonding sites.
So a monomer should at least be bi-functional to undergo polymerization.
Significance: Depending on the functionality of the monomer used, linear,
branched or three dimensional cross linked polymers are obtained.
Functionality of molecule = No of reactive sites

11. continue...
• Bi-functional – Two reactive sites.
If the monomers are bifunctional then linear polymers are obtained.
Thus they are generally of thermoplastic in nature and usually obtained
by addition polymerization.
Examples: Ethylene, Acrylonitrile,propene , vinylchloride (reaction at
double bond), etc.
polymerization
polymerization
Functionality=2
Functionality=2
n
n

12. polymerization
• Trifunctional – Three reactive sites.
If the monomer is trifunctional then cross linked polymers are obtained. They
are thermosets and usually obtained by condensation polymerization.
Examples : Phenol (substitution reaction due to replaceable hydrogen at three
sites), glycerol, etc.
Each chain is held together by covalent bonds. So the movement of chain is
restricted. This type of polymers is hard and brittle,and possesses high
strength, high heat resistance. They are insoluble in solvents.
Functionality=2
n

13. cross linked structure
n
• In a mixture of bifunctional and trifunctional, the ratio decides whether
the polymer shall be branched or cross linked.
• When bifunctional molecule is greater than trifunctional molecules,
branched polymer is obtained (n>>b).
n b
polymerization
polymerization
Branched polymeric structure

14. • When trifunctional molecule is greater than bifunctional molecules
cross linked polymer is obtained (n>>b).
b n
Three dimensional network structure
• Tetrafunctional – Four reactive sites.
Examples : Acetylene (reaction at triple bond), divinylbenzene, etc.

15. polymerization
Functionality=4
Monofunctional
Trifunctional
Functionality Imparted by the presence of easily replaceable hydrogen atoms

16. Based on Classification
Origin or Source Natural or Synthetic polymers
Physical State Amorphous, Crystalline Polymers
Backbone Inorganic and Organic Polymers
Homopolymers, Heteropolymers and Copolymers
Structure Linear Polymers,Branched Polymers,Crossed linked Polymers,Graft
Polymers,Blocked Polymers
Tacticity Isotactic,Syndiotactic. Atactic polymers
Thermal characteristics Thermoplastic, Thermosets
Types of Polymerization Addition Polymerization
Copolymerisation
Condensation Polymerization
Applications Fiber,Elastomers, Plastics,Resins

17. • Classification Based on Source: Natural, Synthetic
 Natural polymers: Synthesized in nature (OR) Isolated from natural
materials.
Examples: Cotton, Silk, Wool, starch, protein, glycogen, rubber, etc.
 Synthetic polymers: Man made (OR) Synthesized from low molecular
weight compounds.
Examples: Nylon, Ethylene, etc.
• Classification Based on Physical state: Amorphous, Crystalline
 Amorphous polymers: A polymer with less ordered arrangement of
chains and weak inter molecular forces.

18. Example: Vinyl polymers etc.
 Crystalline polymers: A polymer with ordered structure that has been
allowed to disentangle and form crystals. The intermolecular forces are
high. So greater strength and higher density.
Example: Cellulose etc.
•Classification Based on Back bone: Inorganic, Organic polymer
 Inorganic polymers: A polymer with a skeletal structure that does not
include carbon atoms in the backbone.
Example: Sculpture nitride, Silicon carbide, Glass Silica, etc.
 Organic polymers: Contains organic frame work.
Example: Polyethylene, polystyrene, Polyethylene, etc.

19. •Classification Based on Structure: Linear, Branched polymers, Cross
linked polymers, Graft copolymers, Block copolymers,Alternate
copolymers and Random copolymers
HDPE
 Linear polymers: Contains linear chain. Example: HDPE (High
density polyethylene).
 Branched polymers: Contains branches or extension attached to the
polymer chain.
Example: LDPE(low density polyethylene).

20. LDPE
 Cross linked polymers: Contains cross links
that are covalent bonds, between two or more
linear polymeric chains.
Examples: Bakelite, any thermosets, etc.
 Graft copolymers: A branched copolymer in
which the backbone and the branches
consists of different monomers.
Examples: Vinyl chloride – acrylonitrile
copolymer, etc.
 Block copolymers: A copolymer with a long
sequence of one monomer followed
by long sequence of another monomer.
(M1) m X (M2) n.
Bakelite

21. Graft copolymer Block copolymer
• Classification Based on Tacticity:Isotactic , Atactic and Syndiotactic
polymers
• Tacticity is the arrangement of pendant groups in space. This orientation
of groups results in three types of stereo – regular polymers. (Note:
Pendant groups are groups attached to the main polymer chain or
backbone like methyl groups in polypropylene).
Isotactic polymers: Pendant groups are all on the same side of the
polymer backbone.
Examples: isotactic PP, Isotactic Polystyrene, etc.

22.  Atactic polymers: Pendant groups are arranged randomly on each
side of the polymer backbone.
Examples: atactic PP, Atactic Polystyrene, etc.
Isotactic polystyrene
Atactic polystyrene

23.  Syndiotactic polymer: Pendant groups are arranged alternatively on
each side of the polymer backbone.
Example: syndiotactic PP, syndiotactic Polystyrene, etc.
Syndiotactic polystyrene

24. • Classification Based on Thermal characteristics:
Sr.No Thermoplastic Thermosetting
1 Long straight chained carbon compounds Cross linked compounds
2 Formed by addition polymerization Formed by condensation(step growth)
polymerization
3 Low strength compared to thermosets More strength compared to thermoplastics
4 Can be processed again and again Cannot be processed again or recycled
5 Eg. Polyethylene Eg. Bakelite,Epoxy
• Classification Based on application or end use:
Fibers
Plastics
Elastomers
Resins

25.  Fibers: The polymer drawn into long filament – like materials, whose
length is at least 100 times. its diameter is called Fiber. Fibers are linear
and drawn in one direction.
Examples: Cotton, Silk, Ethylene, Nylon, etc.
 Plastics: The word plastic originated from Greek, meaning a material
which can be molded or formed into any shape of one’s choice. The
polymer, shaped into hard and tough utility article by the application of
heat and pressure is called plastic.
Few Major types of plastics
Acrylic plastics: PMMA, PAN
Amino plastics: Urea –formaldehyde(UF), MF
Cellulosics: Cellulose nitrate, Cellulose acetate
Vinyl plastics: PVC, PVC-AC
Styrene plastics: PS, ABS

26.  Elastomers: The polymer with good strength and elongation when
vulcanized into rubbery products is called Elastomers.
Examples: Vinyl polymers, natural rubber, silicone rubber, etc.
 Resins Polymers used as adhesives, sealants, etc., in a liquid form is
called resins.
Examples: polysulphide sealants, epoxy adhesives, silicone resin, etc.

27. Focus on the step in front of you, not the whole staircase.