Careers360 Logo
Polymers - Notes, Topics, Formula, Books, FAQs

Polymers - Notes, Topics, Formula, Books, FAQs

Edited By Team Careers360 | Updated on May 06, 2022 11:43 AM IST

Polymer is a term composed of two words i.e poly which means many and mer which means unit. Thus polymer is a bigger molecule made up of various smaller molecules, therefore polymers are also known as macromolecules. Some examples of polymers or macromolecules are polyethene, DNA, protein, Nylon 6,6, etc. The process of formation of polymers by joining the structural units is known as polymerisation.

In this chapter, you will study the various types of polymers that are always around us and play a vital role in our life. Some of the real-life applications of polymers are described below:

  • Polycarbonate is one of the most important polymers. It is used for making eyeglasses.

arv

  • Another polymer is polyamide. Because of its unique properties like durability, moisture resistant, temperature resistance, etc, it is widely used in making the parachutes.
    krv

  • DNA or deoxyribonucleic acid is one such important polymer in the body. Its monomer unit is known as a nucleotide.

DNA

Notes for Polymers

In this section, you will study the important topics of the chapter, overview, formulae and some important tips and guidelines for the preparation of the chapter at the best.

Important Topics

  • Classification of polymers

  • Types of polymerization reactions

  • The molecular mass of polymers

  • Biodegradable polymers

  • Polymers of commercial importance

Related Topics,

Overview of the chapter

In this chapter, you will study the various types of polymers that we use in daily life. In the following section, the classification of polymers is done using different methods.

Classification of polymers

Polymers are classified on the basis of various categories as given below:

(i) Classification of polymers on the basis of source: In this category, polymers are classified on the basis of source of origin:

  • Natural Polymers: These are the polymers that are directly obtained from nature. For example, protein, starch, rubber, etc.

  • Semi-synthetic Polymers: These are those polymers that are prepared in the laboratory by making some modifications in the natural polymers. For example, cellulose nitrate, cellulose acetate, etc.

  • Synthetic Polymers: These are completely man-made polymers and developed in the laboratory. Some common examples are plastic, nylon 6,6, etc.

JEE Main Highest Scoring Chapters & Topics
Just Study 40% Syllabus and Score upto 100%
Download EBook

(ii) Classification of polymers on the basis of structure of polymers:

  • Linear Polymers: These are those polymers that have long and straight chains but no branches. Some common examples include high density polythene, polyvinyl chloride, etc.

  • Branched-chain polymers: These are those polymers that have long chains but also have some branches. Some examples include low-density polythene.

  • Cross-linked or Network polymers: These are the polymers that have a long straight chain but these chains are connected through the strong covalent bonds. Examples are bakelite, melamine, etc.
    cross%20linked

Prepare Online for JEE Main/NEET

Crack JEE 2021 with JEE/NEET Online Preparation Program

Start Now

(iii) Classification of polymers on the basis of mode of polymerization:

  • Addition polymers: These are those polymers that are formed by the repeated addition of monomer. The addition polymers are of two types viz:
    (i) Homopolymers: These are the polymers that are formed by the addition of the same monomers. For example:

    \mathrm {nCH_{2}=CH_{2}\rightarrow (CH_{2}-CH_{2})_{n}}

    (ii) Copolymers: The polymers formed by the addition of different monomers are known as copolymers. For example Buna-S, Buna-N, etc.

  • Condensation polymers: These are those polymers that are formed by the repeated condensation reaction of two different bi-functional or tri-functional monomeric molecules. In these reactions, small molecules such as water, hydrogen chloride, etc eliminate. Some common examples include nylon 6,6, terylene, etc.

    \mathrm{nH_{2}N(CH_{2})_{6}NH_{2}\, +\, nHOOC(CH_{2})_{4}COOH\, \rightarrow \, [NH(CH_{2})_{6}NHCO(CH_{2})_{4}CO]_{n}\, +\, nH_{2}O}

(iv) Classification of polymers on the basis of molecular forces:

  • Elastomers: These are those types of polymers in which the polymer chains are weakly bound to each other. Because of this weak interaction, these polymers have the elastic property. Some crosslinks are also present between the chains due to which these polymers are able to regain their original position. Some examples include buna-S, buna-N, etc.

  • Fibers: These are thread forming polymers. These polymers have high tensile strength and high modulus. They have strong intermolecular forces and thus have crystalline nature. Some examples include polyamides, polyesters, etc.

  • Thermoplastic polymers: These polymers have a long chain of molecules with some branches. These molecules have the property to be softening on heating and hardening on cooling. Their intermolecular forces of attraction are intermediate between elastomers and fibres. Some common examples include polythene, polystyrene, etc.

  • Thermosetting polymers: These are highly branched chain polymers. These polymers cannot be reused. Some common examples include bakelite, urea-formaldehyde resins, etc.

Types of polymerization reactions

There are basically two types of polymerization reactions that you have to study in this chapter.

  • Addition polymerization or chain-growth polymerization: In this type of polymerization reaction, the addition of the same or different type of monomers occurs. These monomers are unsaturated in nature and their addition leads to the long-chain polymers. Examples include high-density polyethylene, Teflon, etc.
  • Condensation polymerization or step-growth polymerization: In this type of polymerization reaction, the repetitive condensation reaction of two bi-functional monomers takes place. This polymerization reaction results in the elimination of small molecules like water, alcohol, etc. Some examples include nylon 6,6, terylene, etc.

The Molecular Mass of Polymers

The molecular mass of polymers differs in different samples. The size and mass of any polymer depend on the number of monomers present in the reaction mixture. The properties of polymers depend upon their size and mass. Thus the molecular mass of any polymer is always measured in terms of average.

Biodegradable polymers

Most of the polymers available to us are non-biodegradable. Thus it has been a major environmental issue to degrade these non-biodegradable polymers. These polymers take a very long time to degrade and thus create so many problems to the environment. To eliminate all these problems, some new biodegradable polymers have been developed as mentioned below:

  • Poly β-hydroxybutyrate – co-β-hydroxy valerate (PHBV
  • Nylon 2–Nylon 6

Polymers of Commercial Importance

Other than the polymers that have been described, there are further many more other polymers that commercial importance. These are described in the table below along with their uses.

Name of PolymerMonomerUses
PolypropenePropeneManufacture of ropes, toys
PolystyreneStyrenewrapping material, manufacture of toys
PVCVinyl chlorideManufacture of raincoats, handbags, water pipes
Urea-formaldehyde resinUrea and formaldehydeManufacture of unbreakable cups
GlyptalEthylene glycol and Phthalic acidManufacture of paints and lacquers
BakelitePhenol and formaldehydeFor making combs, electrical switches

How to prepare for Amines?

  • This chapter is part of organic chemistry. It is completely theory-based. You are not supposed to memorize any formula and numerical practice for getting the good hold on this chapter.

  • In this chapter, you need to remember the names of some important polymers and you also need to take care of the classification section

  • This chapter is not very lengthy, it is easy and remembering the diagrams of polymers is not necessary.

NCERT Notes Subject wise link:

Prescribed Books

For this chapter, first, the NCERT book is best for initial level preparation as well as for board exams. Now, after this, if you want to prepare for competitive exams like JEE and NEET, then these are the best books for you - Morrison and Boyd and R.K Gupta by Arihant publication. Meanwhile, in the preparation, you must continuously give the mock tests for the depth of knowledge. Our platform will help you to provide with the variety of questions for deeper knowledge with the help of videos, articles and mock tests.

NCERT Solutions Subject wise link:

NCERT Exemplar Solutions Subject wise link:

Articles

Questions related to

Question : Read the passage and answer the following questions.
IIT Delhi researchers have designed and fabricated a device that can generate electricity from water drops, raindrops, water streams, and even from ocean waves using "Triboelectric Effect" and "Electrostatic Induction". The device is called "Liquid-solid Interface Triboelectric Nanogenerator". The generated electricity can be stored in batteries for further use. Triboelectric effect is a known phenomenon for a long time, and in this effect, charges are generated when two surfaces are in friction. The best example we see are sparkling lights when we move the blankets/jackets.

The device has a very simple structure consisting of specially designed nanocomposite polymers and contact electrodes and can generate a few Milliwatt mW power, which is sufficient to power small electronic devices like watches, digital thermometers, radio frequency transmitters, healthcare sensors, pedometers. When compared to conventional methods, such as the use of the piezoelectric effect, the present device can generate significantly more electricity.

The researchers successfully incorporated nanostructures into a polymer matrix, which enhanced the film's surface roughness, polarizability, and hydrophobicity, among other characteristics, as a result. Due to the enhancement in the above property, the flexible film is used to fabricate the device where raindrops have just to slide down and can generate electricity. The artificially created rough surface allows to generate more charge and superhydrophobic properties of the solid surface help to roll the water drop without getting stick to the surface.

The IIT Delhi research team also explored the underlying mechanism of the electricity generated when the water drop comes in contact with the solid surface and it is shown that saline water drops generate more electricity. The researchers also showed that the device can even work with ocean waves, where the water is saline, and through the ocean waves contacting the surface of nanocomposite polymer film, electricity is generated.

Question:Name the electronic devices which can be powered with the device mentioned in the passage:
1. Watches
2. Pedometers
3. Refrigerators
4. Radio Frequency Transmitters

 

Option 1: Only 1 and 2
 

Option 2: All 1,2,3, and 4
 

Option 3: Only 3 and 4
 

Option 4: Only 1,2 , and 4

Correct Answer: Only 1,2 , and 4


Solution : The correcrt option is 4 i.e  "Only 1, 2, and 4."
Explanation:

 Let's refer to the following lines of the passage:

The device has a very simple structure consisting of specially designed nanocomposite polymers and contact electrodes and can generate a few Milliwatt (Mw) power, which is sufficient to power small electronic devices like watches, digital thermometers, radio frequency transmitters, healthcare sensors, pedometers. 
The above statement clearly mention the watches, pedometers and radio frequency transmitters.

Back to top