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- (a) What do you understand by polymerisation? Explain the mechanism of polymerisation.
(b) Differentiate between addition and condensation polymerisations. - (a) Explain the following terms:
Co-polymerisation, condensation, smoked rubber.
(b) Why are the plasticisers added to polymers. - (a) What is a rubber and how is it classified?
(b) State the reasons for compounding rubber.
(c) What is artificial rubber? - Differentiate between following:
(a) Thermoplastic and thermosetting plastic.
(b) Addition and condensation polymerisations.
(c) Rubber and Plastic.
(d) Injection and compression mouldings of plastics. - (a) What is vulcanization of rubber and how is it affected?
(b) Give the important characteristics of plastics.
(c) Describe the moulding of plastics. - (a) Give the typical uses of plastics obtained from different moulding processes.
(b) What are the various ingredients of the plastics? Give their specific uses. - (a) Describe the characteristics of PVC.
(b) Write a note on Bakelite.
(c) Describe briefly the fabrication of plastics. - (a) How are plastics classified? State the role of plastic as a building material.
(b) Differentiate between crepe rubber and smoked rubber.
(c) Explain what is meant by depolymerisation. Is it harmful? - (a) State the properties of plastics.
(b) What are the advantages of plastics over the other suitable building materials?
(c) Describe briefly use of plastics as building material. - Discuss:
(a) Stress-strain curve for plastics.
(b) Creep and relaxation in plastics.
(c) Effect of temperature on ultimate elongation of plastics.
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- Polyvinyl chloride (PVC) is a
(a) thermosetting material (b) thermoplastic material
(c) elastoplastic material (d) rigid-plastic material - Plastics are examples of
(a) ceramic materials (b) polymeric materials
(c) anhydrides (d) elastomers - Bakelite plastics are obtained by
(a) addition polymerisation (b) condensation polymerisation
(c) co-polymerisation (d) de-polymerisation