Question

Although styrene undergoes both cationic and anionic polymerization equally well, one method is often preferred with substituted styrenes. Which method is preferred with each compound? Explain.

a.

b.

c.

d.

Short answer

Answer

The electron-donating groups on styrene make it undergo cationic polymerization.

The electron-withdrawing groups on styrene make it undergo anionic polymerization.

Step-by-step solution

Styrene

The molecule styrene is a very reactive monomer, and it undergoes all types of polymerization like free radical, cationic and anionic polymerization. It is the primary monomer in polystyrene.

Option a.

The substituent in this compound is the methoxy group. It is an example of the +I (positive inductive effect) group. So it allows styrene to participate in cationic polymerization.

Option b.

The substituent in this compound is the nitro group. It is an example of the -I (negative inductive effect) group. So it allows styrene to participate in cationic polymerization.

Option c.

The substituent in this compound is the nitro group. It is an example of the -I (negative inductive effect) group. So it allows styrene to participate in cationic polymerization.

Option d.

The substituent in this compound is the methoxy group. It is an example of the +I (positive inductive effect) group. So it allows styrene to participate in cationic polymerization.