Chapter 21, Problem 21.47AP

Interpretation Introduction

(a)

Interpretation:

The structure of Kevlar in polymer notation is to be predicted.

Concept introduction:

Small molecular units join together to make large chain or three dimensional structures, known as polymers. These small molecular units are known as monomers and they join as such or sometimes with the loss of a small molecule like water. Kevlar polymerization is done by the substitution of chlorine atom of $1,4-$ benzenedicarbonyl chloride by amino group of $1,4-$ benzenediamine.

Interpretation Introduction

(b)

Interpretation:

A few repeating units of two Kevlar chains that shows hydrogen-bond donors and acceptor are to be drawn.

Concept introduction:

The hydrogen bonding is weak internal bonding between the molecules. The atoms having lone pair of electrons or high electron density share these electrons partially with adjacent hydrogen. Normally, hydrogen atom is in vicinity of carbons having less electron density. So, the atom sharing its electrons with hydrogen is electron donor and the atom accepting these electrons is known as acceptor.