Question

4. What monomer would you start with to make the polymer shown? Would the polymer be made more effectively using a cationic or an anionic polymerization?

CN CN CN

Answer 1

Polymer is polyacrylonitrile (PAN) Monomer unit is acrylonitrile Generally PAN is prepared from free radical polymerization Commercially PAN is synthesized via free radical method without control over molecular dimension and structure Anionic polymerization can also be used which yields better control But side reactions here are major problem some side reactions are rightarrow i) attack of propagating anion on cyano group ii) attack on proton alpha - to the cyano group To avoid such side reactions and to yield homogeneous polymerisation throughout the process atom transfer radical polymerization (ATRP) is most versatile one This method uses 2-bromopropionitrile as radical initiator CUBr/bipyridine as catalyst and ethylene carbonate as solvent.