Which statement is correct?

We evaluate each statement about polymers to find the correct one.

Option 2 states that Buna-S is a linear thermosetting polymer. This is incorrect because Buna-S (styrene-butadiene rubber) is an elastomer with thermoplastic character, not a thermosetting polymer.

Option 3 states that Buna-N is a natural polymer. This is incorrect because Buna-N (acrylonitrile-butadiene rubber) is a synthetic copolymer of 1,3-butadiene and acrylonitrile.

Option 4 states that Neoprene is an addition copolymer used in plastic bucket manufacturing. This is incorrect because Neoprene is an addition homopolymer made from a single monomer, chloroprene (2-chloro-1,3-butadiene), and it is not used for plastic buckets.

Option 1 states that the synthesis of Buna-S needs nascent oxygen. Buna-S is prepared by the emulsion copolymerisation of 1,3-butadiene and styrene in the presence of a peroxide initiator (such as benzoyl peroxide). The peroxide generates nascent oxygen and free radicals to initiate the polymerisation. Hence this statement is correct.

The correct answer is Option 1.