Natural rubber has the following drawbacks:
1) It is soft and sticky at room temperature. At high temperatures, (> 335 K), softness increases.
At low temperatures, (< 283 K), it is brittle.
Hence, to maintain elasticity, natural rubber can be used in the temperature range of 283 K − 335 K.
2) It can absorb large amounts of water.
3) It's tensile strength is low and it has low resistance to abrasion.
4) It is soluble in non-polar solvents.
5) It is easily attacked by oxidizing agents.
To improve upon these drawbacks, natural rubber is vulcanized. It (along-with sulphur and appropriate additive) is heated at a temperature range between 373 K and 415 K.