Table Of ContentHEIDELBERG SCIENCE LIBRARY
Leo Mandelkern
An Introduction to
Macromolecules
Second Edition
[SI
Springer-Verlag New York Berlin Heidelberg Tokyo
Leo Mandelkern
Professor of Olemistry
The Florida State University
Tallahassee, Florida 32306, U.S.A.
Library of Congress Cataloging in Publication Data
Mandelkern, Leo.
An introduction to macromolecules.
(Heidelberg science library)
Bibliography: p. 156
Includes index.
1. Macromolecules. I. Title. II. Series.
QD381.M37 1983 547.7 83-387
© 1972,1983 by Springer-Verlag New York Inc.
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ISBN- 13: 978-0-387-90796-3 e-ISBN-13: 978-1-4612-5494-2
DOl: 1007/978-1-4612-5494-2
To Berdie and Our Three Sons
PREFACE TO THE SECOND EDITION
The reception of the original volume by students, pedagogues, and reviewers has
been most gratifying. It appears to have both satisfied a need and served a useful
educational purpose. Hence, some ten years later it has been deemed advisable to
bring it up to date, if only in a slightly expanded form. The purpose for writing this
book and its level remain the same.
Many new polymers have been synthesized in the last decade that have found
meaningful and novel uses. Examples of these applications are included in this new
edition. Major advances have also been made in biophysics and in molecular biology,
as well as in our understanding of natural processes on a molecular level. Foremost
among these has been the development of recombinant DNA technology. With it
has come the potential for large scale synthesis of hormones and proteins. These
new developments have also been incorporated into the present volume. It is my
hope that this new edition will still have a widespread appeal to students in all of
the natural sciences whatever their major interest. It should also be of use and inter
est to those starting industrial or academic careers who have not had an extensive
background in macromolecular science.
Tallahassee, Florida Leo Mandelkern
August, 1982
PREFACE TO THE FIRST EDITION
The purpose of this volume is to provide beginning students in the natural
sciences with a very elementary introduction to the structure and properties of
macromolecular substances. Most students, either those who are science majors or
those in a liberal arts program, do not usually have the opportunity to learn about
this important class of molecules until they take advanced courses at a senior or
graduate level. There is thus a serious gap in our educational processes which has
become acute with the widespread recognition of the important role played by
macromolecules in biological systems, their extensive use in a myriad of articles of
commerce, and their intrinsic scientific interest.
We have attempted to rectify this deficiency by presenting a detailed, but non
mathematical, description of all classes of macromolecules. Macromolecules are a
unique class of substances in that they are molecules of extremely high molecular
weight. When certain common structural features are recognized among the different
kinds of macromolecules, they can be treated and analyzed from a unified point of
view. With this approach, we can discuss in one volume macromolecules of biological
interest as well as synthetic materials such as rubbers, glasses, coatings, and fibers.
It is our hope that this volume will appeal to students in introductory chemistry,
biology, and physics courses and will open to them new vistas and horizons that
they would not otherwise experience. It is important to emphasize that it is not
intended to serve as an introduction to research in this field. If, however, we succeed
in stimulating some readers to pursue further study in this area, we shall be
extremely gratified and our efforts will have been well rewarded.
The generous assistance and advice from two colleagues is gratefully acknowl
edged. Professor G. R. Choppin read a portion of the manuscript in draft form and
contributed some very expert advice as to the level and content. Professor K. B.
Hoffman was kind enough to read the entire manuscript. Her suggestions and criti
cisms were invaluable. Without them it is doubtful whether the manuscript would
have been completed. Finally, it is a pleasure to acknowledge Mrs. Suzanne Knuth
and Mrs. Sandra Burkholder, who typed the manuscript and prepared it in final
form. The author is indebted to them for their labors and for the skills that they
brought to the task.
Tallahassee, Florida Leo Mandelkern
February, 1972
TABLE OF CONTENTS
Preface to the Second Edition
Preface to the First Edition
1. Introduction
2. Structural Features and Preparation 4
Classification and Definition 4
Chemical Repeating Units 8
Copolymers 17
Preparation 19
Branching, Cross-Linking, and Network Formation 24
3. Chain Structure 28
Internal Rotation 28
Disordered Chain Conformation 34
Ordered Conformations 40
4. Rubbers and Glasses 54
Rubbers-Introduction 54
Structural Basis for Rubber Elasticity 57
Glass Formation 61
Chemical Structure and Glass Formation 65
Plasticizers 66
S. Crystalline Polymers and Fibers 68
Crystal Structures 68
Crystallization Process 70
Undeformed Crystallization-Morphology and Properties 75
Melting Process-Undeformed Crystallization 82
Fibers 88
Mechanochemistry 94
6. Macromolecules of Biological Importance 100
Introduction 100
Polypeptides 100
Conformational Properties of Polypeptides 104
Proteins-General 109
Fibrous Proteins 113
Globular Proteins 121
Nucleic Acids-General 130
Deoxyribonucleic Acid-DNA 134
Ribonucleic Acids-RNA 143
Epilogue: Macromolecules and Man 153
Annotated Bibliography 156
Index 157
An Introduction to
Macromolecules
Chapter 1
INTRODUCTION
The history of mankind has been divided into a number of eras on the basis of
the material common to the age. Thus, we have passed through the stone, copper,
bronze, and iron ages. The modern epoch may very well be looked back on by his
torians as the Age of Macromolecules. Macromolecules, which are also known as
polymers, provide both the necessities and amenities of life. Some macromolecules
are found in nature in the form of wood, hide, wool, cotton, silk, and rubber. Others
are synthetic, or man-made, and are used in our everyday life in the form of plastics,
fibers, rubbers, packaging material, the paper upon which we write, paints, and
coatings. Macromolecules such as carbohydrates, proteins, and nucleic acids are
fundamental to the biological sustenance of life and are indeed the essence of life
itself. Natural occurring polymers have of course been in use for a very long time.
It is only recently, however, that we have begun to understand the molecular struc
ture of these materials and the relationship that exists between their structure,
properties, and function.
With this new understanding we have been able to use the natural polymers more
effectively and have also been able to devise synthetic materials to replace them.
Natural occurring systems can be reproduced and we can now even create new
macromolecules with properties or combinations of properties that are not paral
leled in nature. Thus, we are living in an age in which new materials are constantly
replacing older ones. The potential and future benefit to mankind of this under
taking appears to be unlimited. We are entering an era where the concern for our
resources and recognition of their limited abundance are of paramount concern.
The development of appropriate substitutes for scarce resources is a matter of major
importance to the national interest and to the welfare of society. Polymeric sub
stances will undoubtedly playa significant role in the endeavor to develop replace
ment materials.
A macromolecule (or "giant molecule" or polymer) is a chemical species of very
high molecular weight. For example, water, H 0, a very common low molecular
2
weight substance, has a molecular weight of 18. This means that 1 mole of water,
6.02 X 1023 molecules, will weigh 18 grams. Benzene, a common organic solvent
which is another low molecular weight substance, has a molecular weight of 78.
However, 1 molecule of natural rubber has a molecular weight of about 1 million,
i.e., 106. One mole of rubber will therefore weigh 106 grams, which is more than
1 ton. This comparison gives us a vivid picture of the difference between polymers
and substances of low molecular weight. The word "polymer" comes from the Greek
and means many parts. The high molecular weight of a polymer is a result of joining
together in long chains, by means of chemical bonds, many thousands of atoms.
The same types of covalent chemical bonds that are involved in the simpler low
molecular weight organic molecules hold these giant molecules together. The kinds
of atoms and their geometric arrangement give each macromolecule its chemical
distinctiveness and thus its particular use and function.
