By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 15 Introduction to Polymer Chemistry students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 15 Introduction to Polymer Chemistry

Classification of Polymers-

  1. Based on source or origin
  2. Based on structure
  3. Based on intermolecular forces
  4. Based on the mode of polymerization
  5. No. of monomers
  6. Biodegradability

Based on source or origin:

  • Natural Jute, linen
  • Synthetic Nylon, terylene
  • Semisynthetic Acetate, rayon

Based on structure:

  • Linear Polyethene
  • Branched-chain Polypropylene
  • Cross-linked vulcanized rubber melamine

Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry

Based on intermolecular forces:

  • Elastomers Neoprene
  • Fibres Nylon-6 polyesters
  • Thermoplastic PVC, Polystyrene
  • Thermosetting Bakelite

Based on mode of polymerization:

  • Addition Polyvinyl chloride
  • Condensation Nylon polyester dacron
  • Ring-opening Nylon-6

No. of monomers:

  • Homopolymers Polyacrylonitrile
  • Copolymers Buna-S, Buna-N

Biodegradability:

  • Biodegradable PHBV
  • Non- biodegradable Bakelite, Nylon

Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 1

Natural rubber: It is a linear polymer of isoprene (2-methyl-1, 3-butadiene), Cis isomer, exhibits elastic property.

Vulcanization of rubber: The effect of vulcanization enhances the properties like stiffness elasticity, toughness etc. of natural rubber
Natural rubber +1-3% sulphur → Rubber is very soft
Natural rubber + 20-30% sulphur → Rubber is hard.

Polyethene:

(1) LDP (Low-density polyethylene)
Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 2

(2) HDP (High density polyethylene)
Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 3

(3) Teflon :
Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 5

Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry

(4) Polyacrylonitrile :
Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 4

(5) Condensation polymerization. (Polyamide, polyester fibres)
Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 6
Example : Nylon-6, Nylon-66, Terylene.

(6) Preparation of bakelite :
Formaldehyde + Phenol → Novolac → Bakelite
Other polymers of formaldehyde

  1. with urea (NH2CONH2) → Moulded plastic
  2. with melamine: formaldehyde + melamine → monomer Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 7 formaldehyde melamine polymer

(7) Preparation of synthetic rubber :

  • Buna-S (SBR) Styrene-butadiene rubber
    Styrene + 1, 3-butadiene → Buna-S
  • Neoprene rubber
    Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 8

(8) Semisynthetic fiber:

Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 9

(9) Biodegradable polymers :

PHBV (polyhydroxy butyrate-CO-β hydroxy valerate)
3-Hydroxy butanoic acid + 3 Hydroxy pentanoic acid Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry 10 PHBV (ester linkage)

Nylon-2-nylon-6
Glycine + amino caproic acid → Nylon -2-nylon-6

Maharashtra Board Class 12 Chemistry Notes Chapter 15 Introduction to Polymer Chemistry

(10) Commercially important polymers :

  • Perspex/acrylic glass
  • Buna N
  • PVC
  • Polyacryl amide
  • Urea-formaldehyde resin
  • Glyptal
  • Polycarbonate
  • Thermocol.