Short Answer TypeDifferentiate between elastomers and fibres on the basis of inter-molecular forces. Give one structural formula of each type of polymers.
Differentiate between chain growth and step growth polymerization. Give the structural formula one polymer of each type.
What is the difference thermo – plastic polymers and thermosetting polymers?
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Thermoplastic polymers |
Thermosetting polymers |
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1. Soften and melt on heating. 2. Can be remoulded, recast and reshaped ? 3. Less brittle. 4. Soluble in some organic solvents. 5. Usually formed by addition polymerization. 6. Usually have linear structures. 7. Examples. Polythene, PVC, Nylon, teflon, etc. |
1. Do not soften on heating but burn if heated for a longer time. 2. Cannot be remoulded or reshaped? 3. More brittle. 4. Insoluble in organic solvents because of three dimensional cross-linking. 5. Formed by condensation polymerization. 6. Have three dimensional cross-linked structures. 7. Bakellite, urea-formaldehyde resin, terylene. |
How are polymers classified into different categories on the basis of intermolecular forces? Give one example of a polymer of each of these categories.
What are elastomers? Write the chemical equation to represent the preparation of Buna-S.
What are the different ways of initiating addition polymerization? Describe one of them for polymerising vinyl chloride.
Long Answer TypeWhy is cationic polymerization preferred in case of vinylic monomers containing electron donating groups?
Short Answer TypeWill you prefer to polymerize acrylo-nitrile under anionic or cationic polymerization conditions? Explain your choice.
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