Chapter 27.6, Problem 10P

(a)

Interpretation Introduction

Interpretation:

The polymerization of $\text{2,2-dimethyloxirane}$ should be described by anionic mechanism.

Concept Introduction:

Anionic polymerization:

• Initiator will be a nucleophile which reacts with the monomer to form a propagating site that is an anion and the initiator can be compounds like sodium amide or butyllithium.
• Nucleophile will attack on the alkene and the alkene contains a substituent that can withdraw electrons by resonance.

(b)

Interpretation Introduction

Interpretation:

The polymerization of $\text{2,2-dimethyloxirane}$ should be described by cationic mechanism.

Concept Introduction:

Cationic polymerization:

• The polymerization in which an electrophile acts as an initiator and adds to the monomer which leads to the formation of a carbocation.
• The initiator widely used is a Lewis acid and in the polymerization the electrophile adds to the ${\text{sp}}^{\text{2}}$ carbon bonded to the most number of hydrogens.