This document summarizes a seminar on polymer science. It introduces polymers, describing them as large molecules composed of repeating structural units bonded together. It then discusses different types of polymer linkages such as linear, branched, and cross-linked polymers. The document also classifies polymers according to their properties into natural/synthetic, organic/inorganic, and thermoplastic/thermosetting polymers. Finally, it covers molecular weight determination and biodegradable polymers.

1. SEMINAR ON
POLYMER SCIENCE
Name: D.Dhivakaran
Reg.no: 192311081
Branch: B.E.CSE
Saveetha school of engineering
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2. • CONTENT:
• Introduction
• Types of Polymer
• Classifications
• Molecular weight determinations
• Bio degradable polymers
• Conclusion
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3. INTRODUCTION
• Definition :
Apolymer is a large molecule (macromolecule)
composed of repeating structural unit connected by covalent
chemical bonds.
- The word is derived from the Greek words (poly), meaning
"many"; and (meros), meaning "part"
Example:- Butadiene ,poly-vinyl-chloride etc.
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4. Types Of Linking In Polymers
• Linear Polymers:
Apolymer in which the molecules form long
chains without branches or cross-linked
structures.
examples: nylon, polyester, PVC etc.
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5. • Branched Polymer:
Apolymer chain having branch points that
connect three or more chain segments.
Examples: polythene, glycogen, starch etc
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6. • Cross linked Polymer:
. Cross-links are bonds that link one polymer chain
to another. They can be covalent bonds or ionic
bonds.
Examples: malamine formaldehyde resin etc
• Cross linked Polymer are know as thermosetting materials.
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7. classification of polymer
(According to their properties & characteristics.)
1) Natural and Synthetic Polymers.
2)Organic and Inorganic Polymers.
3)Thermoplastic and Thermosetting Polymers.
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8. • Natural and Synthetic Polymers:
Natural Polymers Synthetic Polymer
-Cotton -Polyethylene
-silk -PVC
-wool -Nylon
-rubber
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9. 2) Organic and Inorganic Polymers:
• A Polymer whose backbone chain is essentially made of carbon
atoms is termed an Organic polymer.
Examples- cellulose, proteins, polyethylene, nylons.
• A Polymer which does not have carbon atom in their
backbone chain is termed as Inorganic polymer.
Examples- Glass and silicone rubber
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10. 3) Thermoplastic and Thermosetting Polymer:
• Some polymer are soften on heating and can be converted into
any
shape that they can retain on cooling.
• Such polymer that soften on heating and stiffen on cooling are
termed as `thermoplastic’ polymers.
Ex. Polyethylene, PVC, nylon, sealing wax.
• Polymer that become an infusible and insoluble mass on
heating are called ‘thermosetting’ polymers.
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11. • Molecular weight determination
• There are two ways to calculate the
average molecular weight:
1. Number Average Molecular Weight
2. Weight Average Molecular Weight
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12. • Molecular weight determination
1. Number Average Molecular Weight
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Divide the total number of the sample
by the total number of the molecule

13. • Molecular weight determination
2. Weight Average Molecular Weight
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Summing the weights of all the
chains and then dividing by total
number of chain

14. BIO DEGRADABLE POLYMER
• Biodegradable polymers can be classified in two:
• Natural biodegradable polymer
examples: xanthum gum, gaur gum, chitosan, chtin etc.
2. Synthetic biodegradable polymer
examples: Polyanhydrides, Poly( latic acid ) etc.
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15. Conclusion
Polymers are long chain
molecules with properties
dominated by their chain
behaviour and the nature of
their chemical make-up or
constitution

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