Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin
The present work investigates the effect of polyimide and poly(amic acid) content on the properties of epoxy resin. Charpy impact strength increased by 80% and 70% with the addition of 10 wt.% poly(amic acid) and 15 wt.% polyimide, respectively. However, the flexural strength was improved by 95% and...
Збережено в:
| Дата: | 2011 |
|---|---|
| Автори: | , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Фізико-механічний інститут ім. Г.В. Карпенка НАН України
2011
|
| Назва видання: | Фізико-хімічна механіка матеріалів |
| Онлайн доступ: | http://dspace.nbuv.gov.ua/handle/123456789/139156 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin / M. Bakar, M. Okulska-Bożek, M. Zygmunt // Фізико-хімічна механіка матеріалів. — 2011. — Т. 47, № 3. — С. 77-83. — Бібліогр.: 11 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-139156 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-1391562018-06-20T03:12:53Z Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin Bakar, М. Okulska-Bożek, М. Zygmunt, М. The present work investigates the effect of polyimide and poly(amic acid) content on the properties of epoxy resin. Charpy impact strength increased by 80% and 70% with the addition of 10 wt.% poly(amic acid) and 15 wt.% polyimide, respectively. However, the flexural strength was improved by 95% and 73% (in comparison with neat epoxy resin) by the addition of 5 wt.% polyimide and 5 wt.% poly(amic acid), respectively. Moreover, the addition of 10 wt.% polyimide resulted in two fold increase of impact adhesive strength, while the tensile adhesive strength of epoxy was increased by 70% with only 5 wt.% polyimide. Infrared spectra showed that the obtained compositions containing polyimide or poly(amic acid) exhibited a semi-interpenetrating polymer networks structures, characterized by a relatively high flexibility and very good mechanical properties. Досліджено вплив вмісту полііміду (PI) та поліамідної кислоти (PAA) на властивості епоксидної смоли. Виявлено, що після додавання 10% PAA та 70% PI ударна в’язкість збільшується, відповідно, на 80 та 70% порівняно з немодифікованою смолою. З додаванням у полімер 5% PI та PAA міцність на згин підвищується, відповідно, на 95 та 73%. Крім того, за вмісту 10% PI вдвічі збільшилась адгезійна міцність за удару, а за вмісту 5% PI адгезія за розриву зросла тільки на 70% порівняно з немодифікованою смолою. Інфрачервона спектроскопія показала, що композиції епоксидної смоли з PI та PAA мали напіввзаємопроникні сітчасті структури з відносно високими еластичністю та механічними характеристиками. Исследовано влияние содержания полиимида (PI) и полиамидной кислоты (PAA) на свойства эпоксидной смолы. Выявлено, что после добавления 10% PAA и 70% PI ударная вязкость увеличивается, соответственно, на 80 и 70% в сравнении немодифицированной смолой. С добавлением в полимер 5% PI и PAA прочность на изгиб увеличивается, соответственно, на 95 и 73%. Кроме того, при содержании 10% PI вдвое увеличилась адгезионная прочность при ударе, а при содержании 5% PI адгезия при разрыве возросла только на 70% в сравнении с немодифицированной смолой. Инфракрасная спектроскопия показала, что композиции эпоксидной смолы с PI та PAA имели полувзаимопроникаемые сетчатые структури с относительно высокими эластичностью и механическими характеристиками. 2011 Article Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin / M. Bakar, M. Okulska-Bożek, M. Zygmunt // Фізико-хімічна механіка матеріалів. — 2011. — Т. 47, № 3. — С. 77-83. — Бібліогр.: 11 назв. — англ. 0430-6252 http://dspace.nbuv.gov.ua/handle/123456789/139156 en Фізико-хімічна механіка матеріалів Фізико-механічний інститут ім. Г.В. Карпенка НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
The present work investigates the effect of polyimide and poly(amic acid) content on the properties of epoxy resin. Charpy impact strength increased by 80% and 70% with the addition of 10 wt.% poly(amic acid) and 15 wt.% polyimide, respectively. However, the flexural strength was improved by 95% and 73% (in comparison with neat epoxy resin) by the addition of 5 wt.% polyimide and 5 wt.% poly(amic acid), respectively. Moreover, the addition of 10 wt.% polyimide resulted in two fold increase of impact adhesive strength, while the tensile adhesive strength of epoxy was increased by 70% with only 5 wt.% polyimide. Infrared spectra showed that the obtained compositions containing polyimide or poly(amic acid) exhibited a semi-interpenetrating polymer networks structures, characterized by a relatively high flexibility and very good mechanical properties. |
| format |
Article |
| author |
Bakar, М. Okulska-Bożek, М. Zygmunt, М. |
| spellingShingle |
Bakar, М. Okulska-Bożek, М. Zygmunt, М. Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin Фізико-хімічна механіка матеріалів |
| author_facet |
Bakar, М. Okulska-Bożek, М. Zygmunt, М. |
| author_sort |
Bakar, М. |
| title |
Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin |
| title_short |
Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin |
| title_full |
Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin |
| title_fullStr |
Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin |
| title_full_unstemmed |
Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin |
| title_sort |
effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin |
| publisher |
Фізико-механічний інститут ім. Г.В. Карпенка НАН України |
| publishDate |
2011 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/139156 |
| citation_txt |
Effect of poly(amic acid) and polyimide on the adhesive strength and fracture toughness of epoxy resin / M. Bakar, M. Okulska-Bożek, M. Zygmunt // Фізико-хімічна механіка матеріалів. — 2011. — Т. 47, № 3. — С. 77-83. — Бібліогр.: 11 назв. — англ. |
| series |
Фізико-хімічна механіка матеріалів |
| work_keys_str_mv |
AT bakarm effectofpolyamicacidandpolyimideontheadhesivestrengthandfracturetoughnessofepoxyresin AT okulskabozekm effectofpolyamicacidandpolyimideontheadhesivestrengthandfracturetoughnessofepoxyresin AT zygmuntm effectofpolyamicacidandpolyimideontheadhesivestrengthandfracturetoughnessofepoxyresin |
| first_indexed |
2025-07-10T07:42:08Z |
| last_indexed |
2025-07-10T07:42:08Z |
| _version_ |
1837244960809680896 |
| fulltext |
77
Ô³çèêî-õ³ì³÷íà ìåõàí³êà ìàòåð³àë³â. – 2011. – ¹ 3. – Physicochemical Mechanics of Materials
EFFECT OF POLY(AMIC ACID) AND POLYIMIDE ON THE ADHESIVE
STRENGTH AND FRACTURE TOUGHNESS OF EPOXY RESIN
M. BAKAR, M. OKULSKA-BOŻEK, AND M. ZYGMUNT
Radom University of Technology, Radom, Poland
The present work investigates the effect of polyimide and poly(amic acid) content on the
properties of epoxy resin. Charpy impact strength increased by 80% and 70% with the
addition of 10 wt.% poly(amic acid) and 15 wt.% polyimide, respectively. However, the
flexural strength was improved by 95% and 73% (in comparison with neat epoxy resin) by
the addition of 5 wt.% polyimide and 5 wt.% poly(amic acid), respectively. Moreover, the
addition of 10 wt.% polyimide resulted in two fold increase of impact adhesive strength,
while the tensile adhesive strength of epoxy was increased by 70% with only 5 wt.% poly-
imide. Infrared spectra showed that the obtained compositions containing polyimide or
poly(amic acid) exhibited a semi-interpenetrating polymer networks structures, characte-
rized by a relatively high flexibility and very good mechanical properties.
Keywords: epoxy resin, polyimide and poly(amic acid), adhesive strength, impact strength.
Cured epoxy resins are characterized by very good chemical resistance, good pro-
cessing properties and excellent adhesion to metals and glasses. These properties allow
them to be used in various applications such as building, electronics, car industry.
However, their field of application is seriously limited by their low impact strength and
poor resistance to crack propagation. Different types of modifiers were used to improve
the mechanical properties of epoxy resins [1]. Ductile thermoplastics have been used
among others to overcome the drawback of the loss of thermal properties induced by
the incorporation of reactive liquid rubbers such as butadiene – acrylonitrile copoly-
mers terminated with carboxyl or amine groups [2–6].
Agag and Takeichi used the polyimide containing hydroxyl groups to modify a
commercial epoxy resin [7]. Their results showed that the tensile modulus of the
obtained films increased with increasing polyimide content, but with no significant
change in the elongation at break. Moreover, the thermogravimetric analysis showed an
increase in the films thermal stability with the increase of the modifier content.
Gaw and his research group analyzed the cure behavior by differential scanning
calorimetry (DSC) and thermogravimetric analysis (TGA) of an epoxy resin cured with
poly(amic acid)s [8]. The thermal analysis demonstrated a complex reaction between
the polymer matrix and the hardener. However, they did not observe any phase sepa-
ration and attributed the observed phase behavior to a unique in situ reaction.
However, Harris and coworkers synthesized a series of organo-soluble aromatic
polyimides from four different dianhydrides and two different diamines and used them
as toughening agents for epoxy resins [9]. The authors studied the dependence of the
obtained polyimides structure on the solubility, thermal and mechanical properties of
the epoxy based compositions as well as they selected the polyimide to be used as an
effective toughening agent for epoxy resins.
Jin and Park prepared and used a hyperbranched polyimide (HBPI) to modify dig-
lycidyl ether of bisphenol A (DGEBA) [10]. The thermogravimetric analysis results
showed that the thermal stability of the DGEBA/HBPI blends did not obviously change
Corresponding author: M. BAKAR, e-mail: mbakar@wp.pl
78
as the amine-terminated hyperbranched polyimide content increased. However, they
noted an increase of the glass transition temperature as well as an enhancement of the
critical stress intensity factor (KC) and impact strength (IS). The addition of 4 wt.%
polyimide resulted in 2.5 and 2 times increase of KC and IS values. Furthermore, SEM
analysis revealed the occurrence of shear deformation, which led to the crack propa-
gation deceleration within the sample.
More recently, Huang and al. prepared nanocomposites based on polyimide and
epoxy resin [11]. The dynamic mechanical analysis showed a significant increase of
the crosslink densities of the obtained polyimide-epoxy nanocomposites. However,
compressive modulus, hardness and coefficient of thermal expansion changed only
slightly.
The purpose of the present work was to investigate the effect of polyimide and po-
ly(amic acid) content on the adhesive properties and fracture toughness of epoxy resin.
Experimental. Materials. The following ingredients were used in the present work:
– Epoxy resin: Epidian 5 from Organika Sarzyna, Nowa Sarzyna – Poland, having
an average molecular weight of 380 and epoxy number of 0.490...0.520 mol/100 g;
– Polyimide: trade name P-94 from Lenzing AG;
– Hardener: triethylene tetramine (trade name Z1) obtained from Organika Sarzyna;
– Oxydianiline from Fluka AG;
– Pyromellitic dianhydride (Aldrich).
Synthesis of poly(amic acid). Poly(amic acid) was prepared from oxydianiline
(0.005 mol) and pyromellitic dianhydride (0.005 mol) in a solution of tetrahydrofurane
and methanol (4:1 by wt.) by means of polyaddition and dianhydride ring opening me-
thod. Oxydianiline and pyromellitic anhydride were purified by sublimation method under
nitrogen atmosphere After the complete dissolution of diamine under constant mixing,
solid dianhydride was added. The reaction was carried out at room temperature for 2 h.
Samples preparations. Epoxy formulations containing polyimide. Polyimide was
first dissolved in a specific amount of dimethylformamide (ratio: 5 g/45 g) to yield a
10% solution. The dissolution of the polymer was carried out under continuous mixing
by means of mechanical stirrer for 10–12 h and a temperature of 100°C. All the sol-
vents were purified before use. Different amounts of polyimide were added to epoxy
resin and mixed for 5 min using a mechanical stirrer until obtaining a homogeneous
mixture. Then a specific amount of hardener Z1 (12 g Z1/100 g resin) was added follo-
wed by mixing for an additional 5 min. The formulations were then poured to metallic
forms coated with anti-adhesive agent and having the required geometries for impact
and flexural strength measurements.
A specific amount of formulations was spread on solvent cleaned metallic surfa-
ces for adhesive strength under impact and tensile conditions.
All samples were then submitted to curing at room temperature for 24 h followed
by post curing at 120°C for 3 h.
Epoxy samples containing poly(amic acid). Epoxy resin and poly(amic acid) were
mechanically mixed until a homogeneous mixture was obtained. Then the hardener
was incorporated and mixing was continued for an additional 5 min. The formulations
were then poured to metallic forms as previously. Moreover, similarly to polyimide
based compositions, a constant amount of adhesive was spread on solvent cleaned me-
tallic surfaces prior to adhesive strength measurements.
Curing and post-curing processes were carried out as for polyimide samples.
Properties evaluation. The impact strength was evaluated on samples having 8 cm
in length, 1 cm in width, 4 mm in thickness and 1mm of notch using Zwick 5102 appa-
ratus according to Charpy method and Polish norm PN-81/C-89029.
79
The flexural strength was evaluated on samples having the following geometries:
16 mm×10 mm×4 mm using a Dynstat apparatus according to Polish norm PN-72/
C-04243.
The adhesive strength under impact conditions was measured using a Zwick 5102
apparatus by estimating the work needed to separate two jointed metallic plates of
1 cm2 surface area which were adapted to the Charpy hammer.
The tensile adhesive strength was evaluated according to Polish norm PN-69/
C-89301 using two metallic cylinders having 1 cm2 in the base surface area and Instron
tensile tester 5566 with a deformation rate of 5 mm/min.
Infrared spectrophotometer FT-IR Perkin Elmer 1000 PC was used for the analy-
sis of obtained compositions structure.
Results and discussion. The Charpy impact strength (IS) is shown in Fig. 1a as a
function of polyimide (PI) and poly(amic acid) (PAA) content. It can be noted, that IS
increases with increasing amount of PI and PAA. Maximum improvement of 70% (in
comparison with nonmodified resin) is reached with 15 wt.% PI. The impact strength
enhancement might be explained by the significant polyimide toughness at room tem-
perature. Moreover, the addition of 10 wt.% PAA leads to approximately 80% optimum
enhancement of IS in comparison with that of neat epoxy resin. The impact strength
enhancement by poly(amic acid) incorporation can be attributed to the formation of
ether groups arising from PAA which increases the flexibility of the obtained compo-
sition. However, the IS decrease (induced by the higher amount of PAA) might be
explained by the presence of an appreciable amount of stiff segments which prevent the
reactions of ether groups responsible for flexibility improvement.
From Fig. 1b, it can be noted that as polyimide (PI) and poly(amic acid) (PAA)
content is increased, the flexural strength as measured under two point bending method
increases and then decreases.The maximum flexural strength, representing approxi-
mately 95% and 73% in comparison with neat epoxy resin, is obtained with 5 wt.% of
PI and PAA, respectively.
Fig. 1. Effect of polyimide ( ) and poly(amic acid) ( ) content on impact strength (IS)
of the epoxy resin (a) and on its flexural strength (S) (b).
As shown in Fig. 2, the flexural angle at break measured under two-point bending
mode, increases with the addition of polyimide but is not significantly affected by
poly(amic acid) incorporation. As with impact strength results, the maximum value of
flexural angle is exhibited by the composition containing 10 wt.% of polyimide. The
resin flexibility improvement attains 50% in comparison with that of nonmodified
epoxy resin. The epoxy composition flexibility enhancement might be attributed to the
increase of the free volume that is provided to the systems leading to more chain or
segment movements. Consequently, the modified samples undergo larger deformations
before the occurrence of fracture. Moreover the increase in composition flexibility may
explain the increase of the crack propagation resistance (Fig. 1a).
80
The effect of polyimide and
poly(amic acid) content on the impact
adhesive strength as well as tensile adhe-
sive strength are illustrated in Table 1. By
impact adhesive strength (IAS), we mean
the energy needed to separate under im-
pact conditions two metallic plates jointed
by the epoxy based composition, while the
tensile adhesive strength (TAS) is measu-
red under tensile conditions. It can be no-
ted that, as the modifier content increases,
IAS increases and then decreases. The
composition containing 10 wt.% polyimi-
de (PI) shows maximum IAS value which
corresponds to almost twice the IAS value of unmodified epoxy resin. We can explain
the IAS enhancement by the presence of (–NH–) polar groups in the formed epoxy/po-
lyimide structure. However, for poly(amic acid) based compositions, maximum impro-
vement equating 65% in relation with neat epoxy resin, is reached with 5 wt.% PAA. It
is worth noting that all PI and PAA based compositions exhibits higher or at least equal
impact adhesive strength values as the pristine epoxy samples cured with triethylene
tetramine. We can further observe that as the amount of PI increases, the tensile adhe-
sive strength increases then decreases attaining maximum value, representing 70%
increase in comparison with unmodified epoxy resin, with only 5 wt.% PI. The compo-
sition containing 15 wt.% polyimide exhibit higher TAS values than the neat resin.
Table 1. Values of tensile and impact adhesive strength as a function of polyimide
and poly(amic acid) content
Impact adhesive strength, MPa Tensile adhesive strength, MPa Modifier
content, wt.% Polyimide Poly(amic acid) Polyimide Poly(amic acid)
0 1.4 1.4 5.6 5.6
5 1.5 2.3 9.4 3.2
10 2.8 1.9 8.6 3.4
15 1.6 1.7 5.8 7.8
Moreover, it can be noted that the addition of 5 and 10 wt.% of poly(amic acid)
does not result in TAS improvement. However, the enhancement is relatively quite
significant (40% increase in comparison with nonmodified epoxy resin) with the
addition of 15 wt.% PAA. The tensile adhesive strength enhancement is most probably
due to the significant viscosity increase induced by poly(amic acid) imidization.
To analyze the reaction between the epoxy resin and poly(amic acid), composi-
tions containing the epoxy resin without curing agent and epoxy resin modified with
poly(amic acid) and polyimide were prepared and tested for their infrared spectra.
In Fig. 3a infrared spectra of virgin non-crosslinked epoxy resin and composition
containing 35 wt.% of poly(amic acid) are presented.
The analysis of infrared spectra (IR) spectra of epoxy resin containing 35 wt.%
PAA (Fig. 3b) indicates that the peak appearing at 915 cm–1 and corresponding to
epoxy groups is smaller than in epoxy resin without curing agent, as shown in Fig. 3a.
The decrease of the height of the mentioned peak confirms the occurrence of chemical
reaction(s) between epoxy resin and poly(amic acid).
Fig. 2. Effect of polyimide ( )
and poly(amic acid) ( ) content
on the flexural angle at break.
81
Fig. 3. Infrared spectra of epoxy resin without curing agent (a)
and containing 35 wt.% poly(amic acid) (b).
The poly(amic acid) imidization results in the formation of imide groups confir-
med by the presence of peaks appearing at 1787 and 1728 cm–1, which are characteris-
tic for the vibrations of C=O of imide groups. These bands are shifted towards the
lower values (1770 and 1720 cm–1 according to literature), which is the result of graf-
ting between the networks as well as physical interaction between the two involved po-
lymers. This confirms the formation of a semi-interpenetrating polymer network type
structure with physical and chemical bonding between polymer matrix and polymeric
modifier.
Infrared spectra of epoxy resin cured with trietylenetetraamine for 3 h at a tempe-
rature of 110°C is illustrated in Fig. 4a. However, peaks confirming the existence of
hydroxyl as well secondary amine groups is shifted to 3422.5 cm–1. This peak is higher
in the case where epoxy resin is cured at the lower temperature, indicating that cross-
linking takes place in the bulk of the specimen.
Fig. 4. Infrared spectra of epoxy resin cured with trietylenetetraamine (T = 110°C, 3 h) (a)
and modified with 10 wt.% of polyimide (b).
However, one can observe in both cases the appearance of a small peak corres-
ponding to epoxy groups, which confirms the complete curing of the epoxy resin.
From infrared spectra of epoxy resin composition containing 10 wt.% of poly-
imide (PI) presented in Fig. 4b, one can observe, that the peak at 1509.0 cm–1 is smaller
than that of uncured epoxy resin (Fig. 3a), confirming thus, that the addition of poly-
imide leads to the physical as well as chemical modification of epoxy resin.
The peak appearing at 3408.0 cm–1, which corresponds to the vibrations of –OH
groups is more intensive and insignificantly shifted to higher intensities, which demon-
strates the presence of higher amount of such groups in the considered system.
82
The reaction between epoxy resin Epidian 5 and poly(amic acid) can take place
through the reaction of epoxy groups with amine groups of poly(amic acid) as follows
(scheme 1):
Scheme 1
The epoxy groups will react further to yield a more branched structure as indi-
cated below (scheme 2 ):
Scheme 2
Moreover, the reticulation reaction of epoxy resin might take place through the
reaction of terminal amine groups of poly(amic acid) with epoxy groups of the matrix
as follows (scheme 3):
Scheme 3
In this case, the obtained structure is more linear and less branched than in sche-
me 2, which might explain the flexibility increase of the obtained modified compositions.
CONCLUSIONS
Based on the obtained results one can make the following conclusions.
The addition of polyimide resulted in the increase of the flexural strength, the
deflection angle at break, the impact strength as well as adhesive strength under impact
and tensile conditions. The impact strength was improved by approximately 70% and
in comparison with unmodified epoxy resin with the addition of 15 wt.% polyimide.
Moreover, the maximum flexural strength value representing 95% in comparison with
neat epoxy resin, was obtained with 5 wt.% polyimide. The flexibility of epoxy resin
was also improved. The maximum value of flexural angle at break was exhibited by the
composition containing 10 wt.% of polyimide. The enhancement of the mechanical
properties of epoxy resin with polyimide might be due mainly to the high elasticity and
fracture toughness of the modifier.
The addition of poly(amic acid) resulted in the improvement of impact strength,
impact adhesive strength as well as the flexural strength. This latter increased maxi-
mally by about 73% with 5 wt.% of poly(amic acid), while the impact strength was
83
enhanced by approximately 80% with the addition of 10 wt.% poly(amic acid), in com-
parison with that of the neat epoxy resin. The flexibility of epoxy resin was not affec-
ted by poly(amic acid) addition.
Infrared spectroscopy analysis revealed that the obtained structures had semi-in-
terpenetrating polymer networks type structures with the occurrence of chemical reac-
tion between poly(amic acid) and epoxy resin.
РЕЗЮМЕ. Досліджено вплив вмісту полііміду (PI) та поліамідної кислоти (PAA) на
властивості епоксидної смоли. Виявлено, що після додавання 10% PAA та 70% PI ударна
в’язкість збільшується, відповідно, на 80 та 70% порівняно з немодифікованою смолою. З
додаванням у полімер 5% PI та PAA міцність на згин підвищується, відповідно, на 95 та
73%. Крім того, за вмісту 10% PI вдвічі збільшилась адгезійна міцність за удару, а за вміс-
ту 5% PI адгезія за розриву зросла тільки на 70% порівняно з немодифікованою смолою.
Інфрачервона спектроскопія показала, що композиції епоксидної смоли з PI та PAA мали
напіввзаємопроникні сітчасті структури з відносно високими еластичністю та механічни-
ми характеристиками.
РЕЗЮМЕ. Исследовано влияние содержания полиимида (PI) и полиамидной кисло-
ты (PAA) на свойства эпоксидной смолы. Выявлено, что после добавления 10% PAA и
70% PI ударная вязкость увеличивается, соответственно, на 80 и 70% в сравнении немо-
дифицированной смолой. С добавлением в полимер 5% PI и PAA прочность на изгиб уве-
личивается, соответственно, на 95 и 73%. Кроме того, при содержании 10% PI вдвое уве-
личилась адгезионная прочность при ударе, а при содержании 5% PI адгезия при разрыве
возросла только на 70% в сравнении с немодифицированной смолой. Инфракрасная спек-
троскопия показала, что композиции эпоксидной смолы с PI та PAA имели полувзаимо-
проникаемые сетчатые структури с относительно высокими эластичностью и механичес-
кими характеристиками.
Acknowledgements. The authors of the paper would like to acknowledge Mr Marcin
Kostrzewa for the preparation of FTIR spectra.
1. Kinloch A. J. and Young R. J. Fracture Behaviour of Polymers // Appl. Sci. Publishers.
– New York, 1983.
2. Chemical modification of matrix resin networks with engineering thermoplastics / J. L. Hedrick,
I. Yilgor, G. L. Wilkes and J. E. McGrath // Polym. Bull. – 1985. – 13, № 3. – P. 201–208.
3. Bucknal C. B. and Partridge I. K. Phase separation in epoxy resins containing Polyether-
sulphone // Polymer. – 1983. – 24, № 5. – P. 639–644.
4. Hourston D. J., Lane J. M., and MacBeath N. A. Toughening of epoxy resins with thermoplastics
II. Tetrafunctional epoxy-polyetherimide blends // Polym. Intern. – 1991. – 26, № 1. – P. 17–21.
5. Rong M. and Zeng H. Polycarbonate-epoxy semi-interpenetrating polymer network 2. Phase
separation and morphology // Polymer. – 1997. – 38, № 2. – P. 269–277.
6. Effects of mixing temperatures on the morphology and toughness of epoxy/polyamide blends
/ S. Kim, J. Kim, S. H. Lim, W. H. Jo, and C. R. Choe // J. Appl. Polym. Sci. – 1999. – 72,
№ 8. – P. 1055–1063.
7. Agag T. and Takeichi T. Synthesis and characterization of epoxy film cured with reactive
polyimide // Polymer. – 1999. – 40, № 23. – P. 6557–6563.
8. Preparation of polyimide epoxy composites / K. Gaw, M. Kikei, M.-A. Kakimoto, and Y. Imai
// Reactive & functional polymers. – 1996. – 30, № 1. – P. 85–91.
9. A study of polyimide thermoplastics used as tougheners in epoxy resins – structure, property
and solubility relationships / S. Li, B.-L. Hsu, F. Li et al. // Thermochimica Acta. – 1999.
– 340–341. – P. 221–229.
10. Jin F.-L. and Park S.-J. Thermal properties and toughness performance of hyperbranched-
polyimide-modified epoxy resins // J. Polym. Sci. Part B. Polym.-Phys. – 2006. – 44, № 23.
– P. 3348–3356.
11. Thermomechanical properties of polyimide-epoxy nanocomposites from cubic silsesquio-
xane epoxides / J. Huang, Y. Xiao, K. Y. Mya et al. // J. Mater. Chem. – 2004. – 14, № 19.
– P. 2858–2863.
Received 01.10.2009
|