Question

Which of the following is synthetic rubber?
A. Buna – S
B. Neoprene
C. Both (a) and (b)
D. none of these

Answer 1

Hint: A rubber is a polymer that has the ability to be elastic. Rubber is generally extracted from nature called natural rubber, but it can be prepared also as synthetic rubber. It has the property to be stretched and to return to its original shape. It is prepared through various polymerization methods.

Complete answer:
Synthetic rubber is any vulcanized rubber which is capable of getting stretched under an external force and returning to its original size when the force is removed. Synthetic rubbers are made of neoprenes, buna rubbers, etc. So, both Buna – S and neoprene are synthetic rubbers.
Neoprene is prepared by the polymerization of chloroprene that is 2 – chloro – buta – 1,3 – diene. It is used in the manufacturing of shoe heels and gas kits.
Buna – S is a polymer made from the polymerization of the monomers buta – 1,3 – diene and styrene. It is used in making cable insulation, automobile tyres and footwear components.

Hence, Buna – S and neoprene, both are synthetic rubbers. So correct option is C, both (a) and (b) .

Note:
Vulcanization of rubber is the process used to insert sulphur into the natural rubber that increases its tensile strength, elasticity and resistance to abrasion. Buna rubbers include rubbers made from Buna – S and Buna – N. Buna – N is made by polymerization of buta – 1,3 – diene and acrylonitrile; it is used to make oil seals as it is resistant to action of petrol.