Aging of Polymers and Polymeric Materials Caused by Environmental Impact: tutorial: In 2 parts. Part 1

104 Pages·2.217 MB·Russian

by  Cherezova

Copyright ООО «ЦКБ «БИБКОМ» & ООО «Aгентство Kнига-Cервис»
The Ministry of Science and Higher Education of the Russian Federation
Kazan National Research Technological University

AGING OF POLYMERS AND POLYMERIC
MATERIALS CAUSED BY ENVIRONMENTAL
IMPACT

Part 1

Тutorial

Kazan
KNRTU Press
2018
Copyright ООО «ЦКБ «БИБКОМ» & ООО «Aгентство Kнига-Cервис»
UDK 541.64:66 (076.5)

Published by the decision of the Editorial Review Board
of the Kazan National Research Technological University

Reviewers:
Professor, PhD in Chemistry A. Burilov
Associate Professor, PhD in Chemistry S. Egorova

Authors: E. Cherezova, G. Nugumanova, G. Timirbaeva,
Yu. Karaseva
Aging of Polymers and Polymeric Materials Caused by Environmental
Impact : tutorial : In 2 parts. Part 1 / E. Cherezova [et al.]; The Ministry
of Science and Higher Education of the Russian Federation, Kazan
National Research Technological University. – Kazan : KNRTU Press,
2018. – 104 p.

ISBN 978-5-7882-2588-3
ISBN 978-5-7882-2589-0 (p. 1)

The main data on issues of polymer aging caused by various factors are
summarized. The characteristics of macromolecular reactions in addition to thermal,
thermal-oxidative degradation, degradation caused by the aggressive environment,
high-energy radiation, etc. are considered.
The Study Guide is intended for students studying Master Degree Program
18.04.01 «Chemical Engineering» related to such study fields as Chemical
Engineering of Polymers and Polymeric Materials as well as Chemical and Physical
Modification of High Molecular Compounds, Chemical Engineering of Synthetic
Rubber, Chemistry and Physics of High Molecular Compounds, Catalytic
Engineering in Petroleum Chemistry and Polymer Chemistry.
The Study Guide is prepared by Technology of Synthetic Rubber
Department.
UDK 541.64:66 (076.5)

ISBN 978-5-7882-2589-0 (p. 1) © Cherezova E., Nugumanova G.,
ISBN 978-5-7882-2588-3 Timirbaeva G., Karaseva Yu., 2018
© Kazan National Research Technological
University, 2018
Copyright ООО «ЦКБ «БИБКОМ» & ООО «Aгентство Kнига-Cервис»
INTRODUCTION

Polymers are a vitally important creation of
the mankind. Scientists are capable of prolonging
their youth and their working life.

Polymer products change their properties during their processing or
exploitation. These changes are called aging. In the language of science,
aging of polymers is a set of chemical and physical transformations
occurring during treatment, storage, and application of polymers and
leading to the loss of essential properties (physical, mechanical,
thermophysical, electrical and other properties). The process of polymer
aging is accompanied by the damage of structure and architecture of
macromolecules, that is, the change of the number and arrangement of
monomer units in their chain. In a more comprehensive sense, aging can be
called any change of molecular, supramolecular and phase structure of
polymers and polymeric materials.
Actual polymeric material is a complex system including various
specific additives (plasticizers, inhibitors, fillers and others) and admixtures
(traces of catalysts and initiators, metal deactivators and others), alongside
with the main component, a macromolecular compound. That is why the
study of aging requires the research of a wide range of issues and chemical
transformations (radical, ionic and molecular ones) in multi-component
systems. The competing processes of destruction and cross-linking
(structuring) of macromolecules play a key role in these transformations.
Destruction is a process in which the polymer breaks down with the
cleaving of bonds in macromolecules and the formation of
macromolecules’ fragments. In the case of structuring, after the cleaving of
bonds in macromolecules, the formation of new macromolecules from the
formed macromolecules’ fragments occurs.
The traditional problem in the field of stabilizing the properties of
polymers is to preserve the operational properties as long as possible, and,
therefore, to extend the service life of polymer products. Strictly speaking,
stabilization of polymers means a complex of methods for suppressing or
slowing down the processes responsible for aging.
The range of technical requirements for stability and, consequently,
stabilization of polymers is wide. For example, polymer threads used in
surgery serve only a certain period, after which they must spontaneously
break down. On the contrary, polymeric anticorrosive coatings of main oil
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and gas pipelines should fulfill their functions as long as possible. All this
determines numerous tasks to be performed when stabilizing polymer
products.
In the first part of the study guide, the main processes that occur in
polymers under the influence of various physical and chemical factors are
considered. In the second part, methods that allow to slow down the aging
process of polymers are covered.
We hope that the range of issues discussed in the book will be of
interest not only to students but also to post-graduate students.
The authors express their gratitude to S. Sh. Saigitbatalova,
K. A. Medvedeva, the staff members of Technology of Synthetic Rubber
Department, for the technical aid.
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PREFACE

AGING AND STABILIZATION OF POLYMERS.
BACKGROUND

There are no good or bad things, it all
depends on circumstances
Niccolò Machiavelli

The issue of polymer aging makes up a large section of polymer
material science, the science of creating polymeric materials, preserving
and controlling their properties.
Professor Alexander Samojlovich Kuzminsky, who worked at the
Research Institute of Rubber-Processing Industry (now The Research
Institute of Elastomeric Materials and Products, Moscow), was the first in
the world who realized the importance of this field of science for prolonging
the lifetime of polymeric products and predicting the period of their reliable
exploitation. He published the first studies in this field in the forties.
Unfortunately, the world scientific community could not become familiar
with the works of A. S. Kuzminsky, which were published mainly as
research reports of the Institute.
For this reason, Professor Norman Grassie, University of Glasgow,
Scotland, UK, is considered to be the originator of this field of polymer
science, he started to publish his works on aging and stabilization of
polymers ten years later after the publication of the first articles of
A. S. Kuzminsky. Later Professor Gerald Scott from University of
Birmingham started to study the processes of polymer aging. N. Grassie
founded an international journal called Polymer Degradation and Stability
(Pergamon Press, Oxford, UK), emphasizing by this the importance of the
polymer aging issue.
At the end of the fifties of the 20th century, the study of aging and
stabilization of polymers in our country was led by Professor Moisey
Borisoviсh Neyman (The Institute of Chemical Physics of Academy of
Science of the USSR, Moscow). He was asked to deal with these issues by
Nikolay Nilolaevich Semyonov, Director of the Institute of Chemical
Physics, Noble prize winner, a member of the Academy of Sciences,
N.N. Semyonov deserves credit for the creation of the chain chemical
reaction theory. M.B. Neyman applied quantitative parameters to the
research on aging of polymers using chemical kinetics.
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The intensive research on the issues of thermal destruction
(pyrolysis), oxidation, ozonizing, hydrolysis, radiation damage, photo-,
biomechanical destruction of polymers and on the synthesis of stabilizers
for polymers was conducted under the guidance of Nikolay Markovich
Emmanuel1, а member of the Academy of Sciences of the USSR, during
seventies-eighties of the 20th century. The work of studying the
flammability decrease of polymeric materials was started at the end of the
seventies of the 20th century.
The general theory (kinetics and mechanism) of polymer aging and
stabilization was developed owing to this research. The possibility of using
destruction processes as a method of modification of polymeric products’
properties was shown.
The Russian scientists Anatoly Leonidovich Buchachenko, Gennady
Efremovich Zaikov, Evgeny Timofeevich Denisov, Viktor Yakovlevich
Shlyapintokh, Yuriy Aleksandrovich Shlyapnikov, Oleg Nikiforovich
Karpukhin and a number of others (the Institute of Chemical Physics of the
Russian Academy of Sciences) played a key role in the development of the
theory of radical reactions in solutions and solid polymers during oxidation,
photodegradation. Their research has contributed greatly to the creation of
the scientific basis of polymer aging and stabilization, prediction of the
period of reliable exploitation and storage of polymeric products in different
climatic zones of the country.
The extensive fundamental and applied studies in the field of aging
and stabilization of halogen-containing polymers were conducted under the
guidance of Karl Samoylovich Minsker (Bashkir State University, Ufa).
The studies on aging and stabilization of heterochain polymers and
elastomers conducted by Berta Mikhailovna Kovarskaya (The Research
Institute of Polymeric Materials, Moscow), Konstantin Borisovich
Piotrovskiy (The All-Soviet Union Research Institute of Synthetic Rubber,
Leningrad, now The Research Institute of Synthetic Rubber, St. Petersburg),
Petr Anatolyevich Kirpichnikov (Kazan Chemical Technological Institute,
now Kazan National Research Technological University, Kazan) and many
others are of considerable practical importance.
The activity related to creating domestic stabilizers for polymers
started in the seventies of the 20th century. A number of stabilizers were
implemented into practice in Moscow Oil Refinery in Kapotnya
(V. V. Ershov), in the Research Institute of Polymers in Tambov

1 Bibliographical notes on scientists mentioned in the text are given in Appendix.
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(E. G. Rozantsev), at the plants of fine organic synthesis in Sterlitamak
(G. A. Nikiforov, A. G. Liakumovich) and in Ivanovo-Frankovsk (Ukraine,
A. A. Volodkin) and others.
In our country, approximately 700 scientists worked in 100 research
centers solving problems of aging and stabilization of polymers during the
1970s and 1980s.
To date, the number of researchers in our country continuing studies
in this area has significantly decreased. However, we cannot ignore the
groups of actively working scientists under the guidance of Academician
Yury Borisovich Monakov (Bashkir State University, the Institute of
Organic Chemistry of the Bashkir Branch of the Russian Academy of
Sciences, Ufa), Academician Aleksandr Aleksandrovich Berlin (the
Institute of Chemical Physics, Moscow), Corresponding Member of the
Russian Academy of Sciences Peter Anatolyevich Kirpichnikov (Kazan
National Research Technological University, Kazan), Academician of the
Russian Academy of Sciences Ivan Aleksandrovich Novakov (Volgograd
State Technical University, Volgograd), Corresponding Member of the
Russian Academy of Sciences Alexander Vasilyevich Kuchin (the Institute
of Chemistry of the Komi Scientific Center of the Ural Branch of the
Russian Academy of Sciences). About 20-30 famous scientists in the
country periodically refer to this problem while solving other problems.
In general, the world science strengthens its positions in this field,
and Polymer Degradation and Stability journal has increased its capacity
three-fold. Every two years, the MoDeSt Conference (Modification,
Degradation, Stabilization) is held, the international conference The Time
of Polymers and Composites organized by the University of Naples
Federico II has became a traditional one, and there are some other examples.
Now the main attention is shifted to the aging of polymers in
conditions of the polluted atmosphere (oxides of nitrogen, sulfur, etc.),
biodegradation of polymers, prediction of the operation time of polymeric
products in a body (prostheses, retention suture, adhesives, endovascular
therapy with hydrogels, etc.). Studies on reducing the flammability of
polymer materials are successfully developed.
What have we already received and what can we expect from the
solution of the problem of aging and stabilization of polymers?
G. E. Zaikov, Professor of N. M. Emanuel Institute of Biochemical
Physics, an enthusiast and popularizer of the achievements of the Russian
science, answers these questions in the form of the following postulates:
1. Extension of reliable operating time of polymers.
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The increase of service life, for example, twice, is equivalent to the
twofold increase in the manufacture of these polymer products. This is an
important practical task at large-scale production.
2. Forecasting the lifetime of polymer products.
Underestimation of the service life will lead to the withdrawal of
good products, and the overestimation of the operating life will lead to
accidents and, possibly, to lethal outcomes.
3. The use of destruction processes as methods of polymer
modification (creation of new polymeric materials with improved
performance properties).
4. Secondary use of end-of-life polymer products. Numerous
natural resources can be saved due to the recycling of products from
polymers.
5. Creation of polymers with a strictly defined lifetime. Polymers
should be used as long as they are needed, but disappear (decompose)
immediately after they become unnecessary.

References
1. Zaikov, G. E. Starenie i stabilizatsiya polimerov. Komu i zachem eto
nado? [Aging and Stabilization of Polymers. Who needs it and Why?].
Istoricheskiy aspekt himicheskaya fizika i mezoskopiya [Historical Issues of
Chemical Physics and mesoscopy]. 2005. vol. 10, no.1, pp 118-122. (in
Russian).
2. Fedtke, M. Himicheskie reaktsii polimerov. perevod s nem [Chemical
Reactions of Polymers]. Moscow, Khimiya Publ., 1990. 152p (in Russian).
3. Volkov, V. A. Vyidayuschiesya himiki mira [Outstanding Chemists of
the World]. Moscow, Vyisshaya shkola Publ., 1991. 656 p. (in Russian).
4. Zaikov, G. E. Starenie, stabilizatsiya i gorenie polimerov i kompozitov.
O prioritetah v issledovaniyah [Aging, Stabilization and Combustion of
Polymers]. Izvestiya vyisshih uchebnyih zavedeniy. Seriya: Himiya i
himicheskaya tehnologiya [Proceedings of Higher Educational Institutions.
Chemistry and Chemical Technology]. 2010, vol. 53. no.12. pp 143-145.
(in Russian).
5. Zaikov, G. E. Nikolay Markovich Emanuel. K 95-letiyu so dnya
rozhdeniya [Nikolay Markovich Emanuel, to his 95 Years’ Birthday].
Izvesti vyisshih uchebnyih zavedeniy. Seriya: Himiya i himicheskaya
tehnologiya [Proceedings of Higher Educational Institutions. Chemistry
and Chemical Technology]. 2010, vol.53. no.11, pp126-130. (in Russian).
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6. Zaikov, G. E. Gorenie, starenie i stabilizatsiya polimerov, polimernyih
smesey i kompozitov [Aging, Stabilization and Combustion of Polymers,
Polymer Mixtures and Composites]. Izvesti vyisshih uchebnyih zavedeniy.
Seriya: Himiya i himicheskaya tehnologiya [Proceedings of Higher
Educational Institutions. Chemistry and Chemical Technology]. 2011, vol.
54, no.1, pp 110-112. (in Russian).
7. Zaikov, G. E. Gorenie, starenie i stabilizatsiya polimerov, polimernyih
smesey i kompozitov. Obschie soobrazheniya [Aging, Stabilization and
Combustion of Polymers, Polymer Mixtures and Composites]. General
Considerations]. Plasticheskie massyi [Plastics]. 2010, no. 8, pp 62-64. (in
Russian).
8. Zaikov, G. E. Gorenie, starenie i stabilizatsiya polimerov, polimernyih
smesey i kompozitov. Chast 1. Obschie soobrazheniya [Combustion, Aging
and Stabilization of Polymers, Polymer Mixtures and Composites. Part 1.
General Considerations]. Kauchuk i rezina [Rubber and Vulcanized
Rubber]. 2011, no. 2, pp 36-38. (in Russian).
9. Zaikov, G. E. Gorenie, starenie i stabilizatsiya polimerov, polimernyih
smesey i kompozitov. Chast 2. O prioritetah v issledovaniyah [Combustion,
Aging and Stabilization of Polymers, Polymer Mixtures and Composites.
Part 2. About Research Priorities]. Kauchuk i rezina [Rubber and
Vulcanized Rubber]. 2011, no. 2, pp 38-40. (in Russian).
10. Zaikov, G. E. Starenie i stabilizatsiya polimerov (komu i zachem eto
nado? Istoricheskiy aspekt) [Aging and Stabilization of Polymers. Who
needs it and Why? Historical Issues]. Kauchuk i rezina [Rubber and
Vulcanized Rubber]. 2008, no. 4, pp 10-13. (in Russian).
11. Stoyanov, O. V. Professor Gennadiy Efremovich Zaikov. Shestdesyat
let v nauke [Professor Gennadiy Efremovich Zaikov. Sixty Years in
Science] Vestnik Kazanskogo tehnologicheskogo universiteta [Herald of
Kazan Technological University]. 2014, vol. 17, no. 24, pp 9-12. (in
Russian).
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1. MACROMOLECULAR REACTIONS

1.1. Particular Characteristics of Chemical Transformations
in Polymer Chains

Chemical processes change the structure and physical properties of
polymers. Whereas, their structural and physical properties strongly affect
the course and speed of chemical transformations of the polymer.
There are two historical stages in the development of ideas about the
reactivity of functional groups of macromolecules. At the first stage, which
began in the 30s of the twentieth century, the study of the chemical reactions
of polymers developed as part of organic chemistry. At the same time, the
approach to macromolecules as typical organic reagents was carried out.
For the primary evaluation of the chemical reactions of polymers, the
«principle of equal reactivity» (Flory-principle) was formulated. According
to this principle, the reactivity of a functional group does not depend on the
fact whether it is attached to a polymer chain or it is in a small molecule.
There are many experimental examples, from which it follows that
the kinetic parameters of various chemical reactions for polymers and low
molecular weight analogs are practically the same (Table 1.1).
However, the wider circle of polymeric objects became, the more
information was accumulated that the reactivity of functional groups of
macromolecules differs from that of low-molecular analogs.
For example, it was observed that the ensemble of even one-type
units of the macromolecule can behave not as the sum of small molecules
of a similar structure with respect to another low-molecular, and certainly
not to a macromolecular reagent. For example, if we compare the bond-
dissociation energy of a hydrogen atom in a series of saturated
hydrocarbons in comparative units, it will be 11 for heptane, 3 for
polyethylene, 2 for polyisobutylene.
Accumulated facts led to the conclusion that the development of the
theory of the reactivity of macromolecular objects requires a special
approach.

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