Revision Notes for CBSE Class 12 Chemistry Chapter 15 (Polymers) - Free PDF Download
FAQs on Polymers Class 12 Notes CBSE Chemistry Chapter 15 (Free PDF Download)
1. What is Polymerization?
As per the NCERT solutions Chapter 15 Class 12 Chemistry Revision Notes, polymerization is a type of chemical reaction where simpler molecules attach to each other to form a macromolecule. The small molecules are monomers. They bond with each other chemically to form a polymer. The best examples are polypropylene, polyethylene, etc.
2. What are Polymers as Per Origin?
If you refer to the NCERT Class 12 Revision Notes Chemistry Chapter 15 solution, you will find that there are two types of polymers, natural, synthetic, and semi-synthetic. You will find a proper explanation in the revision notes.
3. How to Prepare this Chapter on Polymers?
After completing studying this chapter, proceed to the Class 12 Notes Polymers for revision. You will be able to remember what you have studied and can answer the questions.
4. What are polymers?
Polymers can be defined as macromolecules that contain higher molecular mass and are formed by the combination of simple molecules (Monomers) in large quantities. Monomers are converted into polymers through the process of polymerisation. Here’s an example to understand this process.
Example - The polymer polythene is formed through the addition of multiple numbers of ethene (monomer) under 1000 to 2000 atm of pressure, temperature between 350 to 570 K with some traces of oxygen.
5. Write the classification of polymers based on sources.
The three types of polymers are classified on the basis of sources of occurrences.
Natural Polymers - These types of polymers are found in nature or from plants or animals. Example - natural rubber, proteins, etc.
Semisynthetic Polymers - These polymers are created by adding synthetic materials to natural polymers. Example- cellulose acetate, nitrocellulose, etc.
Synthetic Polymers - These polymers are man-made and are created by artificial means in the labs. Example - Teflon, polyethene, nylon, etc.
6. Write the classification of polymers on the basis of structure.
There are three types of polymers on the basis of structure.
Linear Polymers - These polymers contain straight and long chains of monomers. Example - high-density nylon, polyvinyl chloride, polythene, etc.
Branched-chain Polymers - These polymers contain straight chains of monomers with some branches. Example- low-density glycogen, polythene, etc.
Network Polymers or Cross-linked Polymers - These polymers are made from trifunctional and bifunctional monomers. They contain strong covalent bonds between several linear chains of polymers. Example - melamine, bakelite, etc.
7. Write classification of polymers based on polymerisation.
There are two types of polymers based on polymerisation.
Addition Polymers - These types of polymers are made by the repeated addition of different or similar kinds of monomers. The monomers used in the process are unsaturated compounds like alkadienes, alkenes and their derivatives. An example of addition polymers is polythene.
Condensation Polymers - These polymers are formed by the repeated condensation of different trifunctional or bifunctional units of monomers along with the elimination of small molecules such as hydrogen chloride, alcohol, water, etc. Examples- Terylene, Nylon-6,6, Nylon-6.
8. Write different types of polymerisation reactions.
There are two types of polymerisation reactions.
Addition Polymerisation - This type of polymerisation includes the addition of monomer units successively to an extending chain of polymers having a reactive intermediate species like anion or free radical. Addition polymerisation is classified into three types of mechanisms based on the nature of reactive species. They are free radical polymerisation, cationic polymerisation and anionic polymerisation.
Condensation Polymerisation - The process occurs in independent steps or reactions. Every step involves the condensation of two or more bifunctional monomer units with the elimination of small molecules like water or alcohol. Example- dacron, bakelite, etc.

















