The question asks us to identify what the 'S' stands for in the polymer "Buna-S". To solve this, let's briefly discuss the composition and naming of the polymer:
Buna-N: Often used for nitrile rubber that involves "Acrylonitrile".
Buna-S: This is a type of synthetic rubber, specifically a copolymer, formed by the polymerization of butadiene and styrene.
Therefore, in the name "Buna-S":
'Bu': represents butadiene.
'Na': originally comes from sodium, used in the polymerization process.
'S': stands for styrene, which is a key component of Buna-S rubber. Styrene is a monomer derived from benzene and is used to enhance the strength and durability of the polymer.
Now, let's evaluate the options given:
Sulphur: Sulphur is often used in the vulcanization process of rubber but is not related to the name 'Buna-S'.
Strength: Although styrene increases the strength of the polymer, 'Strength' is not directly related to the name.
Styrene: Correct, as explained above, this is the correct answer.
Sulphonation: A chemical process, but not related to the name.
