Differentiate 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.
Chain growth polymerization |
Step-growth Polymerization |
1.Concentration of monomers decreases steadily throughout the reaction. |
1.Monomers disappear early in the reaction |
2.Only one repeating unit is added at a time. |
Any two species present can react. |
3.Increase in reaction time increase the yield but molecular mass is affected very little. |
3. Long reaction time is essential to get high molecular mass polymer. example: |
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.
Why is cationic polymerization preferred in case of vinylic monomers containing electron donating groups?
Will you prefer to polymerize acrylo-nitrile under anionic or cationic polymerization conditions? Explain your choice.