Chapter 26, Problem 26.72P

Interpretation Introduction

(a)

Interpretation:

Polycarbophil is a dietary fiber supplement. It is the calcium salt of a copolymer of acrylic acid and divinylglycol, a cross-linking agent. In the stomach, the calcium ions exchange for protons and in the higher pH of the intestine, the polymer absorbs $\text{70}$ times its mass inwater. A structure for polycarbophil is to be proposed.

Concept introduction:

Polycarbophil is synthesized from copolymerization of acrylic acid and divinyl glycol. A molecule of divinylglycol is incorporated in a poly(acrylic acid) structure which leads to forming the radical and due to which, the second growth of the poly(acrylic acid) takes place which results in the formation of the cross-linked polymer.

Interpretation Introduction

(b)

Interpretation:

Polycarbophil is a dietary fiber supplement. It is thecalcium salt of a copolymer of acrylic acid and divinylglycol, a cross-linking agent. In the stomach, the calcium ions exchange for protons and, in the higher pH of the intestine, the polymer absorbs $\text{70}$ times its mass inwater. It is to be explained why the cross-linking of the polymer is necessary for the given application.

Concept introduction:

Polycarbophil is synthesized from copolymerization of acrylic acid and divinyl glycol. A molecule of divinylglycol is incorporated in a poly(acrylic acid) structure which leads to forming the radical, and due to which, the second growth of the poly(acrylic acid) takes place which results in the formation of the cross-linked polymer. The cross-linked polymer is water-insoluble.

Interpretation Introduction

(c)

Interpretation:

It is to be explained why polycarbophil effective at providing bulk in the intestine and what will occur on a molecular level to polycarbophil.

Concept introduction:

Polycarbophil is synthesized from copolymerization of acrylic acid and divinyl glycol. A molecule of divinylglycol is incorporated in a poly(acrylic acid) structure which leads to forming the radical, and due to which, the second growth of the poly(acrylic acid) takes place which results in the formation of the cross-linked polymer. The cross-linked polymer is water-insoluble. In carboxylic acid, a strong H-bonding takes place.