Question

The structure of some important polymers is given. Which one represents Buna-S?

Answer 1

Hint: To answer this question we should know that Buna-S is a polymer of Butadiene and Styrene. Now you have to just identify the structure that consists of these monomeric units.

Complete step by step answer:
-We should know that Buna-S is also known as styrene-butadiene. Buna-S name is derived from Bu-butadiene, Na-sodium, and S-styrene
-This is a replacement for natural rubber.
-This is derived from two monomers, styrene, and butadiene.
-It has good abrasion resistance and good aging stability when protected by additives.
-It is the most commonly used synthetic rubber.
-Preparation of Buna-S:
 It is a random copolymer formed by the emulsion polymerization of a mixture of 1:3 butadiene and styrene in the presence of peroxide catalyst at 5 degrees Celsius and therefore the product obtained, is called cold rubber. The rubber obtained is also called Styrene-butadiene rubber (SBR).

Generally, It is used for the manufacture of passenger car tires and treads, motorcycle and scooter tires, cycle tires, and tubes.

-Therefore, we conclude that the correct answer to this question is option B.

Note: Here option C represents Buna-N. Buna-N is a polymer whose monomers are 1,3-butadiene and acrylonitrile.

We can also call it Nitrile-Butadiene-Rubber. It is a copolymer.
This rubber is used in seals, belts, oil seals, etc and also used for making synthetic leather and footwear.
The commercial name for this rubber is NBR.