How are polymers classified into different categories on the basis of intermolecular forces? Give one example of a polymer of each of these categories.
(1) Elastomers: They have weakest intermolecular forces of attraction. They are elastic in nature. For example natural rubber, vulcanised rubber.
(2) Fibres: They are polymers having stronger forces having hydrogen-bonds. They have high tensile strength. For example: nylon, terylene.
(3) Thermoplastics: They can be easily moulded into desired shape by heating and then cooling. The force of attraction is intermediate between elastomers and fibres. For example: polythene, polypropone.
(4) Thermosetting plastics: They have the maximum force of attraction because they are cross-linked. They do not become soft on heating. For example Bakelite.
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.
Differentiate between chain growth and step growth polymerization. Give the structural formula one polymer of each type.
Differentiate between elastomers and fibres on the basis of inter-molecular forces. Give one structural formula of each type of polymers.
