Table Of ContentSome Other IUPAC Titles of Interest from Pergamon Press
Books
ANGUS: International Thermodynamic Tables of the Fluid State, 7-Propylene
BATTINO: Oxygen and Ozone
BROWN & DA VIES: Organ-Directed Toxicity—Chemical Indices and Mechanisms
CIARDELLI & GIUSTI: Structural Order in Polymers
EGAN & WEST: Collaborative Interlaboratory Studies in Chemical Analysis
FREIDLINA & SKOROVA: Organic Sulfur Chemistry
FUWA: Recent Advances in Analytical Spectroscopy
GOETHALS: Polymeric Amines and Ammonium Salts
GOODWIN & BRITTON: Carotenoids
HÖGFELDT: Stability Constants of Metal-Ion Complexes, Part A: Inorganic Ligands
KORNHAUSER, RAO & WADDINGTON: Chemical Education in the Seventies
LAIDLER: Frontiers of Chemistry
LAURENT: Coordination Chemistry—21
PERRIN: Stability Constants of Metal-Ion Complexes, Part B: Organic Ligands
RIGAUDY & KLESNEY: Nomenclature of Organic Chemistry
ST-PIERRE & BROWN: Future Sources of Organic Raw Materials
STEC: Phosphorus Chemistry Directed Towards Biology
TROST & HUTCHINSON: Organic Synthesis—Today and Tomorrow
YOUNG: Hydrogen and Deuterium
YOUNG: Oxides of Nitrogen
Journals
CHEMISTRY INTERNATIONAL, the news magazine for chemists in all fields of
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PURE AND APPLIED CHEMISTRY, the international research journal publishing
proceedings of IUPAC conferences, nomenclature rules and technical reports.
INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY
(Macromolecular Division)
in conjunction with
Centre National de la Recherche Scientifique
Université Louis Pasteur de Strasbourg
MACROMOLECULES
Main Lectures Presented at the
27th International Symposium on Macromolecules
Strasbourg, France, 6-9 July 1981
Edited by
H. BENOIT and P. REMPP
Centre de Recherches sur Jes MacromoJecuJes
Strasbourg, France
PERGAMON PRESS
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Copyright © 1982 International Union of Pure and
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AJJ flights Reserved. No part of this publication may be
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First edition 1982
Library of Congress Cataloging in Publication Data
International Symposium on Macromolecules (27th: 1981:
Strasbourg, France)
Macromolecules: main lectures presented at the 27th
International Symposium on Macromolecules, Strasbourg,
France, 6-9 July 1981.
(IUPAC symposium series)
1. Macromolecules—Congresses. I. Benoit, Henri,
1921— II. Rempp, P. III. International Union of
Pure and Applied Chemistry. IV. Université Louis
Pasteur de Strasbourg. V. Title. VI. Series.
QD380.I58 1981 547.7 81-23481
AACR2
British Library Cataloguing in Publication Data
International Symposium on Macromolecules
[27th: 1981: Strasbourg]
Macromolecules.—(IUPAC symposium series)
1. Polymers and polymerization—Congresses
I. Benoit, H. II. Rempp, P. III. International
Union of Pure and Applied Chemistry. Macromoiecuiar
Division IV. Series
547.7 QD380
ISBN 0-08-026226-0
In order to make this volume available as economically
and as rapidly as possible the authors' typescripts have
been reproduced in their originaJ forms. This method un
fortunately has its typographical limitations but it is
hoped that they in no way distract the reader.
Printed in Great Britain by A. Wheaton 6- Co. Ltd., Exeter
SCIENTIFIC COMMITTEE
Honorary Chairmen
G. Champetier (Deceased), C. Sadron
Chairman
H. Benoit
Vice-Chairmen
P. Sigwalt, C. Wippler
Members
A. Banderet, E. Bouchez, M. Carrega, A. Chapiro, J.-B. Donnet,
E. Guillet, A. Guyot, A. Kepes, A.-J. Kovacs, 3. Minoux,
J. Neel, C. Pinazzi, C. Quivoron, P. Rempp,
M. Rinaudo, B. Sillion, A. de Vries
INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY
IUPAC Secretariat: Bank Court Chambers, 2-3 Pound Way,
Cowley Centre, Oxford OX 4 3YF, UK
PREFACE
This book is a collection of the Main Lectures which
were delivered during the 27th IUPAC Symposium on Macromolecules
that was held in Strasbourg , July 6 to 9, 1981.
The purpose of these lectures was to present and
illustrate each of the themes selected by the scientific committee.
These fields were chosen for their importance in Macromolecular
Science and with the feeling that they were representative of the
present trends in Polymer Research.
Qualified lecturers were selected for their own con
tributions to the corresponding domains. They were asked before
hand to report not only on their own work, but also on the present
state of knowledge and on the possible developements and potential
applications in the field in which they are involved. The authors
of Main Lectures originate from countries in which Polymer Science
is most actively investigated, and a world-wide distribution of
invited speakers was achieved.
These considerations will explain the broad field covered
by this book. It contains topics ranging from Pure Polymer
Chemistry to Polymer Physics and Polymer Technology. This illustrates
the diversity of the interest of scientists involved in Polymer
Science and shows once more the pluridisciplinarity of our field.
In a certain way, this is not the kind of book in which
a specialist of a given topic will gain new information or results
in his domain of interest. The purpose of this book is to allow
anybody interested to get precise and up-to-date information on the
present state of research in the domains selected. It should be
specially valuable for scientists who try to keep contact with
progress in Polymer Science beyond their own field of activity. It
should also provide for new ideas, encourage collaboration, and
possibly lead to new applications.
Besides the Main Lectures some 320 short communications
have been presented at the IUPAC Symposium in Strasbourg. These
short communications will not be published as such, but two volumes
of preprints have been made available for the participants. Addi
tional copies can be obtained from the Centre de Recherches sur
les Macromolécules by anybody wanting more details on the Meeting.
Twenty-nine years ago, a similar IUPAC Symposium was
held in Strasbourg, gathering fewer than 200 scientists, but most
of the pioneers of Polymer Science. In 1981 there were about 1000
people attending, on selected topics. One can rejoice in the huge
developements of our scientific discipline, for it illustrate the
growing interest in Polymer Science and Technology and the increa
sing importance of Scientific Research in the present world.
We want to express our deep appreciation to the authors
of the Main Lectures for having prepared and made available a
written version of their presentation to the IUPAC Symposium. We
know that this takes time and requires much care, and we feel
indebted to them.
Preface
We would also like to express our warmest thanks to
all the researchers, technicians and students of the Centre de
Recherches sur les Macromolécules, Strasbourg, and of the
Ecole d'Application des Hauts Polymères, Strasbourg for having
participated actively and willingly in the organisation of the
Meeting. Without their time-consuming help it would have been
impossible to set up such a Symposium. Last, but not least, we
would like to acknowledge the financial support of Franch
Public Research Bodies (CNRS, DGRST, DRET) and of numerous
French Industries devoted to Polymer production and processing.
H. BENOIT P. REMPP
Centre de Recherches sur les Macromolécules
6,rue Boussingault - 67083 STRASBOURG(France)
Septembre 1981
ON COMMON TENDENCIES OF NON-EQUILIBRIUM POLYCONDENSATION
V.V. Korshak
Institute of Organo-Element Compounds, Acad. Sci. USSR,
117813 Moscow, USSR
Abstract - The chemistry of polycondensation processes has
gained a rather rapid development at the present time. All
known polycondensation reactions can be combined into two
groups: 1; equilibrium and 2) non-equilibrium polycondensa
tion. They differ in the equilibrium constant of the process
under investigation. Equilibrium polycondensation includes
reactions with K <10-% reactions with K > 10-* belong to
non-equilibrium process. The difference between these two
polycondensation types shows up in the properties of the re
sulting polymers, the mechanism of elementary reactions, the
nature and mechanism of catalyst action, the kinetics, the
molecular weight distribution, the mechanism of copolycon-
densation, the structure of copolymers and the like. Various
side reactions also occur. As a result, anomalous units are
formed in the macromolecule which gives rise to "raznozven-
ny" (different-unit) polymers. Their structure can be des-
cribed by the following formula: . ^ . ^^
with M as
normal unit and A as anomalous one. Anomalous units and,
as a consequence, polymer raznozvennost (different-unit
structure) have been shown to present in different classes
of polymers prepared by polycondensation methods. Catalysts
strongly influence the non-equilibrium polycondensation pro
cess. The use of tertiary amines makes it possible to cont
rol the structure of the resulting polymers and to produce
conformational-specific polymers.
In 1833 Gay-Lussak and Pelouze obtained the first synthetic polyester by
polycondensation of the hydroxycarboxylic acid (1). In the following years
we observed an ever-increasing number of investigations concerning the poly
condensation field (2-4).
Thus at the present time the polycondensation as a synthetic process has gi
ven a large number of polymeric structures to science and engineering and
played an important role in the development of basic concepts of polymer
science (2-4;. The rapid progress of investigations of polymer synthesis
by polycondensation has enriched the polymer science with new reactions for
polymer preparation, made it possible to understand the mechanism of poly
condensation processes and enlarged a store of science with many new poly
mers.
Some Specific Features of Polycondensation
Polycondensation processes essentially differ from polymerization processes
(2 & 3). First of all, attention should be given to great universality of
polycondensation processes and, consequently, to great variety of structures
prepared with their help. The structures obtained by polymerization are less
diversified than those obtained by polycondensation. Among the polymers ob
tained by polycondensation is a great number of polymers having high thermo-
stability, conductive polymers, physiologically active polymers and the like.
Although the polycondensation is studied nowadays by a more narrow circle of
workers than the polymerization, the effectiveness of their synthetic inves
tigations is rather high (4). Thus, when considering various polymeric com
pounds reported in scientific papers one can find that nearly 50% of new po
lymers described in the literature are polymers produced by means of poly-
l
2 V. V. Korshak
condensation reactions (4). And finally, 1 would say, the most important di
fference consists in that these two processes strongly differ from each ot
her in the number of chemical reactions used in both cases. In polymeriza
tion we make use only of two chemical reactions: addition to double and tri
ple bonds between two atoms or addition to cycles. As to polycondensation,
some dozens of chemical reactions are used in it already at the present
time, and the number of reactions being drawn into these transformations
increases from year to year. This is also true of a very important field
such as biopolymers which are also mainly formed by means of polycondensa
tion methods. It should be emphasized that polycondensation is of great
importance as a method of natural polymer synthesis, since many significant
biopolymers such as proteins, nucleic acids, natural caoutchouc, cellulose,
starch, glycogen, chitin, pentosanes and many other polymers, as well as
ferments, enzymes, and hormones are formed in living organisms by means of
various polycondensation processes, that is, this process is widely repre
sented in nature. And such still quite a new, but very promising domain of
polymer science as inorganic polymers is almost completely the area of poly
condensation application, because most heterochain inorganic polymers are
prepared just by polycondensation (5 & 6).
After such brief characteristic of specific features of polycondensation we
dwell on the modern state of this field, giving particular consideration to
distinguishing features of non-equilibrium polycondensation, to causes of
the rise of raznozvennost in non-equilibrium polycondensation, as well as to
the process of macromolecule formation and the effect of reaction conditi
ons, catalysts and solvents, that is, to questions which nowadays determine
the progress in the polycondensation that finally determines the perspecti
ves of developments in this field•
Types of Polycondensation
Investigation of common tendencies of polycondensation processes has led us
to the conclusion that all known polycondensation reactions can be combined
into two large groups called equilibrium and non-equilibrium polycondensa
tion (2,3t7>8). The difference between them is largely determined by the
value of equilibrium constant (K„) of the process under investigation. ïïqui-
P o
librium polycondensation includes reactions with K„ < 10-^, reactions with
o P
K > 1<y belong to non-equilibrium polycondensation (7 & 8) .
IT
The difference between these two types of polycondensation shows up also in
the properties of the resulting polymers, the mechanism of the proceeding
reactions, the nature and mechanism of catalysts, the kinetics, molecular
weight distribution, the mechanism of copolycondensation, the structure of
copolymers, and other specific features of the process that will be shown
below.
The non-equilibrium process has been studied not so comprehensively, and
this put the task of a detailed investigation of laws governing its course.
The imortance of this trend is caused by that just non-equilibrium polycon
densation makes it possible to synthesize polymers at a higher rate and to
prepare rather high molecular weight polymers with new unit structures and
interesting complex of physical and chemical properties (7 9t10).
f
Functionality of Monomers
Carothers (11) formulated the rule of monomer functionality stating that li
near polymers are formed when the monomers are bifunctional. If they are
three-functional and higher, a gel formation occurs and a steric, insoluble
and infusible polymer is formed. This rule needs radical changes, however,
because there are many cases when this relationship is not confirmed, and
three- and tetrafunctional monomers proved to be capable of forming polymers
with linear macromolecules. This is possible in case of significant diffe
rence in reactivity of functional groups, when the more reactive groups
react earlier forming a linear polymer. This can be exemplified by the reac
tion of glycerine with phthalic anhydride«
Reaction conditions are also of importance. For instance, the non-equilibri
um polycondensation of tetramine with terephthaloyl chloride gives a three-
dimensional insoluble polymer. If the reaction proceeds in pyridine hydro-
chloride or in the salt of another aminé, a linear polymer is formed, al
though the monomer is tetrafunctional. But in this medium it acts as a di-
functional compound (13):
On Common Tendencies of Non-Equilibrium Polycondensation 3
H NAJ^MH -CORCO-NH-V^im-COKCO-
"2O" v ""20
E^YYm2 HCl-C^N , HCl.H^YY^- 1101 01CORCOC1 ..
HC1 -H„N WNH «HOI
0
^ ^,
-CORCO-NH'V^NH-CORCO-
(1)
There is a distinct difference between potential or structural and real or
reactive functionality (13)» Steric factors can be of rather essential im
portance. This can be exemplified by non-equilibrium polycondensation reac
tions, for instance, by the formation of various polyheteroarylenes, when
tetrafunctional compounds such as tetraamines, dihydroxydiamines, dithiadia-
mines, tetracarboxylic acids, diaminodicarboxylic acids and other similar
compounds of the general formula:
(2)
are used as monomers. Important in this case is the mutual position of func
tional groups. If the position enables the formation of five- and six-mem-
bered cycles, linear macromolecules of heterocyclochain polymers are formed
due to a steric effect of functional groups. This fact demonstrates the pos
sibility of preparing linear polymers from three- and tetrafunctional mono
mers that earlier was considered to be impossible. Therefore, it should be
concluded that important for the formation of linear polymers is not only
the common functionality of monomers, but also the corresponding favourable
mutual position of functional groups in the structural unit or monomers as
well as the effect of reaction medium and reaction conditions in the course
of polycondensation. This makes one to pose differently the problem of the
importance of monomer fimctionality in a non-equilibrium polycondensation
The Rule of Non-Equivalence of functional Groups
As known, the rule of non-equivalence of functional groups holds for the
reactions of dicarboxylic acids with glycols or diamines and generally for
all cases of polycondensation when the initial substances are bifunctional
(2,13). Tais principle provides a means of controlling the molecular weight
of polymers prepared by equilibrium polycondensation when different quanti
ties of monofunctional substances or an excess of one of the monomers are
added (13).
Figure 1 shows the changes of found and calculated molecular weight as a
function of the excess of one of the monomers. Investigations of this re
lation for non-equilibrium polycondensation with initial substances having
higher functionality showed that in most cases here again the excess of one
of the initial substances has similar effect in the reactions of tetrafunc
tional monomers decreasing the molecular weight proportionally to the
excess of one of the monomers. Such a dependence was observed in many cases
of non-equilibrium polycondensation.
The reaction of various tetrafunctional nucleophiles with tetracarboxylic
acids or their derivatives follows the rule of non-equivalency of functio
nal groups, as shown in the general form in Fig. 2.
4 V. V. Korshak
100 80 SO hO 20 0 20 40 60 80 100
Excess Excess
component A component B
Fig. 1. Dependence of the molecular weight of polyamides on
the excess of one of the monomers. 1,2) calculated, 3) found
molecular weight. P - coefficient of polymerization.
\ red.
k 1 2 M
Nucleofile Electrofile
excess,mole-% excess, mole-
Fig. 2. Influence of excess monomers on the solution viscosi
ty of polymers prepared from various tetrafunctional monomers
(dihydrazides of dicarboxylic acids, bis-o-aminophenols, di-
anilinodiamines, diamides of bis-anthranyl acids; with poly-
carboxylic acids.
Figure 3 shows the dependence of the viscosity of polyimide solution on the
excess of initial substances in the reaction of diamine with pyromellitic
dianhydride (16).
The same occurs in the reaction of carboranedicarboxylic acid dichloride
with tetraamines, as shown in Fig. 4 (16).
Thus, the above examples evidence rather clearly a distinct dependence of
the molecular weight of polymer to be synthesized on the excess of one of
the monomers also in the case of tetrafunctional monomers and, consequently,
"the rule of non-equivalency of functional groups" is also valid for many-
functional monomers in a non-equilibrium polycondensation (3 & 13).
