discuss the main purpose of vulcanization of rubber.
Answers
Natural rubber is useful but has problems associated with its use. The disadvantages of natural rubber are as follows:
1. Natural rubber is sticky and soft at room temperature. At elevated temperatures i.e grater than 335 K, it becomes even softer. At low temperatures i.e less than 283K, it becomes brittle. Therefore natural rubber can be used only at temperature range of 283 K-335 K to maintain its elasticity.
2. It absorbs large amount of water
3. It has low resistance to abrasion and low tensile strength.
4. It is soluble in non-polar solvents.
5. Can be easily attacked by oxidizing agents.
Vulcanization is done mainly to improve the properties of natural rubber. In this process, a mixture of raw rubber with sulphur and appropriate additive is heated at a temperature range between 373 K and 415 K.
Answer:
Vulcanization of natural rubber is done to improve upon all these properties. In this process, a mixture of raw rubber with sulphur and appropriate additive is heated at a temperature range between 373 K and 415 K. This is a slow process,therefore some additives like zinc oxide etc are used to accelerate the proess.