Chapter 17.5, Problem 17.25P

Interpretation Introduction

Interpretation:

The structure of repeating unit in Nomex which is made from the given compounds has to be given.

Concept introduction:

In chemistry structure is the arrangement of chemical bonds between atoms in a molecule, specifically which atoms are chemically bonded to what other atoms with what kind of chemical bond.

Carboxylic acid: One $-OH$ group is attached to the carbonyl carbon atom of the compound. It is represented as $RCOOH$

Amide: One $-N{H}_2$, $-NHR\text{'}$ or $-NR{\text{'}}_2$ group is attached to the carbonyl carbon atom of the compound. It is represented as $RCONR{\text{'}}_2$.

Amide Formation: Amide is formed when a carboxylic acid reacts with an amine or ammonia.

Here, the $-OH$ group is attached to the carbonyl carbon atom of the carboxylic acid is being replaced by $-N{H}_2$, $-NHR\text{'}$ or $-NR{\text{'}}_2$ group in the an amine or ammonia forming amide and water.

Polyamide: One $-COOH$ group of a dicarboxylic acid reacts with the one of the amino groups of a diamine results in the formation of an amide between them. Repeated linking of more molecule results in the formation of a polymer with amide linkage called polyamide.