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Why is cationic polymerisation preferred...

Why is cationic polymerisation preferred in case of vinyl monomers containing electron donating groups.

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Cationic polymerisation is cạrried out in presence'of ạcids. When a proton adds to a vinyl monomer, carbocation intermediate is formed. Since presence of electron donating groups stabilizes the carbocation formed in the initiațion step as well as in the chain propagation step. 'therefore' vinyl monomers containing electron dọnating groups preferably undergo cationic polymerisation. Initiation step: figure Propagation step: figure
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