Chapter 26, Problem 26.76P

Interpretation Introduction

(a)

Interpretation:

The synthesis of a polyurea is to be proposed from the synthesis of polyurethanes.

Concept introduction:

The $\text{O-}\left(\text{C=O}\right)\text{-N}$ motif is repeated in polyurethane, and in the case of polyurea, the repeating unit is $\text{N-}\left(\text{C=O}\right)\text{-N}$. For this $\text{N-}\left(\text{C=O}\right)\text{-N}$ motif, instead of ethylene glycol, ethylene diamine(${\text{H}}_{\text{2}}{\text{N-CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{-NH}}_{\text{2}}$) is used in the synthesis of polyurea. In a synthesis of polyurethane, toluene diisocyanate and ethylene glycol are used, so in the synthesis of polyurea, toluene diisocyanate and ethylene diamine are used.

Interpretation Introduction

(b)

Interpretation:

The condensed formula for polyurea is to be drawn.

Concept introduction:

The $\text{O-}\left(\text{C=O}\right)\text{-N}$ motif is repeated in polyurethane, and in the case of polyurea, the repeating unit is $\text{N-}\left(\text{C=O}\right)\text{-N}$. For this $\text{N-}\left(\text{C=O}\right)\text{-N}$ motif, instead of ethylene glycol, ethylene diamine(${\text{H}}_{\text{2}}{\text{N-CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{-NH}}_{\text{2}}$) is used in a synthesis of polyurea. In a synthesis of polyurethane, toluene diisocyanate and ethylene glycol are used, so in the synthesis of polyurea, toluene diisocyanate and ethylene diamine are used.