Podcast
Questions and Answers
Polyacrylonitrile is a substitute for silk in making commercial fibers.
Polyacrylonitrile is a substitute for silk in making commercial fibers.
False
Buna S is a type of natural rubber.
Buna S is a type of natural rubber.
False
Neoprene is a type of synthetic rubber.
Neoprene is a type of synthetic rubber.
True
Vulcanization of rubber involves heating it with oxygen.
Vulcanization of rubber involves heating it with oxygen.
Signup and view all the answers
Poly Vinyl Chloride is a type of synthetic fiber.
Poly Vinyl Chloride is a type of synthetic fiber.
Signup and view all the answers
Addition polymerization involves the condensation of monomers with double and triple bonds.
Addition polymerization involves the condensation of monomers with double and triple bonds.
Signup and view all the answers
Condensation polymerization involves the addition of monomers with double and triple bonds.
Condensation polymerization involves the addition of monomers with double and triple bonds.
Signup and view all the answers
Nylon 6,6 is obtained by heating caprolactum with water.
Nylon 6,6 is obtained by heating caprolactum with water.
Signup and view all the answers
Terelene is a type of polyamide.
Terelene is a type of polyamide.
Signup and view all the answers
Bakelite is a type of polyamide.
Bakelite is a type of polyamide.
Signup and view all the answers
Study Notes
Polymerization
- Polymers are macromolecules formed by joining of repeating structural units on a large scale.
- The repeating structural units are called Monomers.
Monomers and Polymers
- Monomers are small molecules that combine with each other to form polymer molecules.
- Macromolecules refer to large molecules built from smaller subunits.
- When all the subunits are of the same type, the macromolecules are called polymers, and the subunits are monomers.
- Examples of polymers: DNA, proteins, carbohydrates.
- Example of macromolecule: triglycerides (fat).
Classification of Polymers
Based on Source
- Natural polymers: occur in nature (e.g. protein, nucleic acid, cellulose, starch).
- Semi-synthetic polymers: derived from natural sources, but undergo chemical treatment (e.g. cellulose nitrate, cellulose acetate).
- Synthetic polymers: man-made (e.g. plastics, Nylon, Buna-s, PVC, polyethylene).
Based on Structure
- Linear polymers: long chains (e.g. high-density polythene, polyvinyl chloride).
- Branched chain polymers: chain with branches (e.g. low-density polythene).
- Cross-linked or network polymers: string covalent bond between chains (e.g. Bakelite, Melamine).
Based on Type of Monomer
- Homo polymer: made from only one monomer (e.g. A-A-A-A-A-A-A-A).
- Co-polymer: made from two or more different monomers.
- Types of co-polymers:
- Random copolymer: -A-B-B-A-B-A-A-B-
- Alternating copolymer: -A-B-A-B-A-B-A-B-
- Block copolymer: -A-A-A-A-B-B-B-B-
- Graft copolymer:
- Types of co-polymers:
Based on Molecular Forces
- Elastomers: weakest intermolecular forces (e.g. rubber, buna-S).
- Fibers: strongest intermolecular forces (e.g. Nylon, Polyesters, Terylene).
- Thermoplastic: can be remolded by heating and cooling (e.g. Polythene, PVC).
- Thermosetting Plastic: cannot be reused (e.g. Bakelite, urea formaldehyde).
Based on Mode of Polymerization
- Addition polymerization: monomer contains one double bond.
- Condensation polymerization: monomer contains bi-functional group.
Addition Polymerization
- Examples of addition polymers:
- Polythene (two types)
- Teflon (Polytetrafluoroethene)
- Polyacrylonitrile
- Buna S
- Natural Rubber (cis-1,4-poly isoprene)
- Synthetic Rubber (Neoprene, Buna-N)
- Poly Vinyl Chloride (PVC)
- Poly styrene
Vulcanization of Rubber
- Heating with sulphur and an additive to improve physical properties of natural rubber.
Mechanism of Addition Polymerization
- Step 1: Chain initiating step
- Step 2: Chain propagation
- Step 3: Chain termination
Condensation Polymerization
- Involves repetitive condensation between two bi-functional monomers, with loss of simple molecules (e.g. water, alcohol).
- Examples:
- Polyamides (Nylon 6,6, Nylon 6)
- Polyesters (Terelene, Glyptal)
- Phenol Formaldehyde Polymer (Bakelite)
- Melamine Formaldehyde Polymer
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about polymers, macromolecules formed by joining repeating structural units, and understand the process of polymerization and the differences between polymers and macromolecules.
