Epoxy Resin Chemistry II

310 Pages·1983·4.57 MB·English

by  Ronald S. Bauer (Eds.)

Epoxy Resi y
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
Epoxy Resin Chemistry II
Ronald S. Bauer, EDITOR
Shell Development Company
Based on a symposium sponsored
by the ACS Division
of Organic Coatings and
Plastics Chemistry
at the 183rd Meeting
of the American Chemical Society,
Las Vegas, Nevada,
March 28-April 2, 1982
A C S S Y M P O S I U M SERIES 221
AMERICAN CHEMICAL SOCIETY
1983
WASHINGTON, D.C.
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
Library of Congress Cataloging in Publication Data
Epoxy resin chemistry II.
(ACS symposium series, ISSN 0097-6156; 221)
Includes bibliographies and index.
1. Epoxy resins—Congresses. I. Bauer, Ronald S.,
1932- . II. American Chemica
of Organic Coatings and Plastic
Epoxy resin chemistry 2. IV. Series
TP1180.E6E588 1983 668'.374 83-6385
ISBN 0-8412-0777-1
Copyright © 1983
American Chemical Society
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In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
ACS Symposium Series
M. Joa
Advisory Board
David L. Allara Robert Ory
Robert Baker Geoffrey D. Parfitt
Donald D. Dollberg Theodore Provder
Brian M. Harney Charles N. Satterfield
W. Jeffrey Howe Dennis Schuetzle
Herbert D. Kaesz Davis L. Temple, Jr.
Marvin Margoshes Charles S. Tuesday
Donald E. Moreland C. Grant Willson
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
FOREWORD
The ACS SYMPOSIUM SERIES was founded in 1974 to provide
a medium for publishing symposia quickly in book form. The
format of the Series parallels that of the continuing ADVANCES
IN CHEMISTRY SERIES except that in order to save time the
papers are not typeset but are reproduced as they are sub
mitted by the authors in camera-ready form. Papers are re
viewed under the supervision of the Editors with the assistance
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integrity of the symposia; however, verbatim reproductions of
previously published papers are not accepted. Both reviews
and reports of research are acceptable since symposia may
embrace both types of presentation.
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
PREFACE
^Νοτ MANY SYNTHETIC ORGANIC MATERIALS rival epoxy resins in their
diversity of application. Th
protective coatings, adhesives
commercial flooring systems is a testimony to the versatility and high
performance characteristics of these materials. Although epoxy resin sales
have not achieved the volumes that commodity-type thermoplastic mate­
rials have, their growth has been impressive. Introduced commercially in
the United States in the late 1940s, epoxy resins achieved annual sales of
about 13 million pounds by 1954. In 1981, total demand was about 319
million pounds, and that figure is expected to grow to 510 million pounds
in 1990.
Future demands for epoxy resins will depend largely on the results of
research such as described in this volume, as well as the outcome of future
efforts. As judged by the number of publications appearing each year on
epoxy resins, the research effort devoted to these materials has not shown
any sign of easing. A survey of the number of publications appearing per
year between 1971 and 1981 that refer to epoxy resins and that are cited in
"Chemical Abstracts" indicates that the number has remained relatively
constant (see Table), at between 2200 and 2300.
The symposium on which this volume is based was an attempt to rep­
resent a cross-section of the current research being conducted on epoxy
resins. Included is work on efforts to improve the performance of existing
products through rubber modifications that will expand markets for resins
and innovative products based on currently available commercial resins.
Also discussed is the work in progress to develop a better understanding
of the properties of cured systems so as to obtain from them their ultimate
performance. If the research effort of the last decade is sustained through
the next decade, the new innovations in epoxy resins could create a demand
for resin that would easily exceed current expectations. When the ingenuity
of chemists and engineers is coupled with the versatility and high perform-
ix
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
ance characteristics of epoxy resins, the result will be the development of
a multitude of new end-uses and currently unanticipated markets.
Number of Epoxy Resin Publications Cited in
"Chemical Abstracts" Between 1971 and 1981
Year of
Publication Patents Nonpatents Total
1981 u n 824 2241
1980 1944 910 2314
1979 1198 1108 2306
1978 1165 1087 2252
1977 1131 1073 2204
1976
1975
1974 1320 861 2181
1973 1109 840 1949
1972 941 144 1785
1971 684 737 1421
RONALD S. BAUER
Shell Development Company
Houston, Texas 77001
February 1982
χ
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
1
Elastomer-Modified Epoxy Resins in Coatings
Applications
R. S. DRAKE and D. R. EGAN
Β F Goodrich Chemical Group, Cleveland, OH 44131
W. T. MURPHY
Β F Goodrich Company, Research and Development Center, Brecksville, OH 44141
Elastomer-modified epoxy resins have grown in usage
in the past 15 year
connected with structura
civil engineering/construction, electrical laminates/
encapsulants and corrosion resistance. Some of this
increased attention has come about through utility of
telechelic butadiene/acrylonitrile liquid polymers.
Both carboxyl and amine reactive liquid polymers (CTBN
and ATBN) have provided chemistries amenable to this
modification with the polybutadiene/acrylonitrile co­
polymer providing solubility parameters close to if
not equaling those of base epoxy resins. It has only
been within the last few years that similar elasto­
mer-modified epoxy resins have been examined in epoxy
coatings and primers. This chapter reviews a portion
of that relatively new journal and patent literature
involving epoxy coal-tar, powder, photo-curable and
solventless heavy duty coatings as well as metal
primers. These examples are employed to illustrate
such benefits of elastomer inclusion as reverse im­
pact, bending/crimping, corrosion resistance, ther­
mal shock resistance and coating adhesion. The
chapter concludes with an initial reporting on in­
dustrial maintenance and marine coatings based on
elastomer-modified epoxy resin models. Similar
benefits are noted with these traditional solvent­
-based coatings under ambient cure.
Numerous blends or alloys of thermosetting resins with elas­
tomers have been developed over the past four decades and found
their way into continuing commercial use. A generous amount of
this has been related to toughening needs : Overcoming the brit-
tleness of highly crosslinked glassy polymers. With i t came the
recognition that not only was degree of elastomer/resin compati­
bility important but also the need for achieving a dispersed phase
0097-6156/8 3/0221-0001$06.00/0
© 1983 American Chemical Society
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.
2 EPOXY RESIN CHEMISTRY
with particle size integrity. Thus, both blended or alloyed
products, as well as the processing techniques for achieving them,
were optimized and later improved upon. Products for both struc­
tural and non-structural applications proliferated.
Among the earlier developments of elastomer/resin blends, the
polybutadiene/acrylonitrile or 1nitrile* elastomer modification of
phenol-formaldehyde condensation resins serves as a typical exam­
ple and a pivot for this paper's thesis as well. The nitrile-
phenolic category of products attests to a large and continuing
literature showing first the usage of nitrile elastomers them­
selves and later their carboxylic analogs. Systematic evaluations
of elastic phenol-formaldehyde molding compositions, e.g., with
both carboxylic and analogous noncarboxylic elastomers are useful
in demonstrating the stronger reinforcement properties of the car-
boxy 1-reactive species
It is these solid carboxyli
to show utility in the modificatio
needs for solid elastomer inclusion, particularly in liquid epoxy
resins, have not always been advantageous. Associated problems
include gel, viscosity threshold limitations and achieving desired
rubber levels in excess of 5-6 phr. Sometimes processing must be
carried out in selected solvents, not always a desirable or
tolerable step.
In the mid-60's carboxyl-terminated polybutadiene/acrylo­
nitrile (CTBN) liquid polymers were introduced for the purpose of
epoxy resin modification. These telechelic polymers are essen­
tially macromolecular diacids. They offer processing ease (and
therefore advantage) over the solid carboxylic nitrile elastomers.
It is no surprise that the epoxy prepreg industry (adhesive and
non-adhesive varieties) found the liquid and solid carboxylic
nitrile elastomer species useful together in processing liquid and
lower molecular weight solid epoxy resins where elastomer modifi­
cation was needed.
Later, in 1974, amine reactive versions of the liquid nitrile
polymers (ATBN) were issued, thereby offering another way to in­
troduce rubbery segments into a cured epoxy resin network. Refer­
ences are cited which provide detailed discussions of nitrile rub­
ber, carboxylic nitrile rubber and both carboxyl- and amine-ter-
minated nitrile liquid polymers (1-4). Table I illustrates CTBN
and ATBN products structurally. Table II provides properties for
typical solid carboxylic nitrile elastomers.
It is the purpose of this review paper to examine the rela­
tively newer uses of these elastomer types as resin modifiers
within the broad range of epoxy-based coating systems.
Elastomer-Modified Epoxy Resin Preparation
Wide-ranging documentation exists which covers modification
of epoxy resins using carboxyl-terminated polybutadiene/acrylo­
nitrile liquid polymers in which addition esterification (alky-
In Epoxy Resin Chemistry II; Bauer, R.;
ACS Symposium Series; American Chemical Society: Washington, DC, 1983.