Indian Forest Service (Mains), Chemistry optional · 2023 · Paper II
Q7(b). Sequential anionic polymerization
Question
Identify A, B and C when styrene reacts with n-BuLi/THF, then butadiene, then ROH.
Answer in brief
A is living polystyryllithium; B is a living styrene–butadiene block copolymer; ROH protonates its chain end to give C.
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Coversliving anionic polymerizationn-BuLiblock copolymerSBS rubberpolystyryllithium
All parts of Question 7
- 7(a) Photochemistry of a rigid aryl ketone5 marks
- 7(b) Sequential anionic polymerization5 marks
- 7(c) Neoprene and chloroprene5 marks
- 7(d) Why polymers have average molar masses5 marks
- 7(e) Two unsaturated ester isomers5 marks
- 7(f) Sanger determination of the N terminus5 marks
- 7(g) Chemical-shift separation in Hz5 marks
- 7(h) Hydration of phenylacetylene5 marks