Chapter 28.6, Problem 19P

Interpretation Introduction

(a)

Interpretation: The structure of prepolymer A formed from $1,4$-dihydroxybenzene and excess epichlorohydrin is to be stated.

Concept introduction: Epoxides are strained three-membered rings. They undergo anionic polymerization to afford the ring opening, by following the ${\text{S}}_{\text{N}}\text{2}$ pathway. The ring opening in an unsymmetrical epoxide takes place at the less substituted or the more accessible carbon atom.

Interpretation Introduction

(b)

Interpretation: The structure of cross-linked polymer B formed from the treatment of A with ${\text{H}}_{\text{2}}{\text{NCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$ is to be stated.

Concept introduction: Epoxides are strained three-membered rings. They undergo anionic polymerization to afford the ring opening, by following the ${\text{S}}_{\text{N}}\text{2}$ pathway. The ring opening in an unsymmetrical epoxide takes place at the less substituted or the more accessible carbon atom.