Which statement is correct?
- (A)Buna-S is a synthetic and linear thermosetting polymer.
- (B)Synthesis of Buna-S needs nascent oxygen.✓ Correct
- (C)Neoprene is an addition copolymer used in plastic bucket manufacturing.
- (D)Buna-N is a natural polymer.
Answer: (B)
Solution
Buna-S is obtained by copolymerising 1,3-butadiene with styrene, the chain being started by nascent oxygen. The chains it forms are linear and it softens on heating, so it is a thermoplastic elastomer rather than a thermosetting polymer. Buna-N, the copolymer of 1,3-butadiene with acrylonitrile, is synthetic in the same way and is not a natural polymer. Neoprene, the addition polymer of chloroprene, resists oils and is used for conveyor belts and gaskets, not for plastic buckets, which are made of polythene. What holds among these statements is that the synthesis of Buna-S needs nascent oxygen.
JEE Main · 2021 · 25 Feb 2021 · Shift 1 · Single correct option