This document discusses the classification and medical applications of polymers. It classifies polymers based on their source as natural, semi-synthetic, or synthetic. Polymers are also classified based on their backbone, structure, mode of polymerization, and molecular forces. Thermoplastic polymers can be reshaped upon heating while thermosetting polymers set permanently. The document outlines several medical applications of polymers including their use in artificial joints, vascular grafts, and artificial lenses.

1. ADHIYAMAN ARTS AND SCIENCE COLLEGE FOR
WOMEN-UTHANGARAI
PG DEPARTMENT OF CHEMISTRY
CLASSIFICATION AND MEDICAL
APPLICATION OF POLYMER
S.KAVITHA
III-CHEMISTRY-B

2. POLYMER CHEMISTRY

3. POLYMERIZATION:
The process by which the monomers get
combined and transformed into polymers is known
as polymerization.
n [Monomer] → Polymer

5. Classification Based on Source:
[1] Natural Polymers : These polymers are found in
plants and animals . e.g. proteins, cellulose, starch.
[2] Semi-synthetic Polymers: Polymers obtained by
making some modification in natural polymers by
artificial means, are known as semi synthetic
polymers. e.g. cellulose acetate(rayon), vulcanized
rubber etc.
[3] Synthetic Polymers : synthetic polymers are
man-made polymers, e.g., polythene, synthetic
rubber, PVC, nylon-66,Teflon, orlon etc.

6. Classification based on backbone
Organic polymers: A polymer backbone chain
essentially is made of carbon atom. E.g. pvc,
protein, polyethylene, polypropylene, cellulose.
Inorganic polymers : A polymer backbone
contains no carbon atom . e.g. Glass and
silicone rubber.

7. Classification based on structure
linear polymer:
These are the polymers in which the monomer
units are linked to one another to form long linear
chains.
Branched Polymers:
These polymers contain linear chains having some
branches, e.g., low density polythene

8. Cross-linked Polymers or Network polymer:
polymers, the monomer unit linked together to form three
dimensional network. These are expected to be quite hard,
rigid and brittle.
E.g., Bakelite, glyptal, melamine-formaldehyde polymer
etc.

9. Classification Based on Mode of Polymerization:
Addition polymers:
The polymers formed by the polymerization of monomers
containing double or triple bonds (unsaturated
compounds) are called addition polymers.
Example: polyethylene

10. Condensation polymerization:
The condensation polymers are formed by
repeated condensation reaction between two different bi-
functional or tri-functional monomeric units. Elimination
of small molecule.
example : polyester

11. Classification based on molecular force
Elastomers :
These are rubber like solid polymers in which the
polymer chains are held together by weakest
intermolecular forces.
e.g., natural rubber, Buna-S, Buna-N etc
Fibres:
Fibres belong to a class of polymers which are
thread-like and can be woven into fabrics.
e.g. nylon-66, terylene and polyacrylonitrile

12. Thermoplastic Polymers:
Some polymers soften on heating and can be converted into
any shape that they can retain on cooling. Thus, they can be
cast into different shapes by using suitable moulds .
e.g., polyethylene and polystyrene.
Thermosetting Polymers: They are like the yolk of egg,
which on heating sets into a mass, and once set, cannot be
reshaped. Such polymers, that become infusible and
insoluble mass on heating, are called ‘thermosetting”
polymers. e.g. Bakelite, melamine-formaldehyde resin and
urea formaldehyde resin.
Order of strength:
thermosetting > fibres > thermoplastic > elastomers

13. Applications of Polymers in Medical Field
A variety of polymers have been used for medical care
including preventive medicine, clinical inspections, and
surgical treatments of diseases.
Polyolefin's:
Its main applications are sliding surfaces of artificial
joints .

14. Polytetrafluoroethylene (PTFE):
PTFE (Teflon) has an ethylene backbone with four
covalently bound fluorine molecules. It’s mainly applied
as vascular graft.
Polymethacrylate:
Its main applications are artificial lens.