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Discuss the main purpose of vulcanisation of rubber. |
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Answer» Solution :NATURAL rubber has the following disadvantages: (i) It is soft and sticky at high temperatures and BRITTLE at low temperatures. Therefore, rubber is generally used in a narrow temperature range (283 - 335 K) where its elasticity is maintained (ii) It has a large water absorption CAPACITY, has low tensile strength and low resistance to abrasion. (III) It is not resistant to the action of organic solvents. (iv) It is easily attacked by oxygen and other oxidising agents. To improve upon the properties of natural rubber, it is vulcanised by heating it with about 5% sulphur at 373-415 K. The vulcanised rubber thus obtained has excellent elasticity over a larger range of temperature, has low water absorption tendency, is resistant to the action of organic solvents and oxidising agents. |
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