Synthesis of Castor Oil-Derived Decanediamide as a
Novel Flexible Asphalt-Modiﬁed Epoxy Resin Curing
KAI HU, LIXIA BAO, XIAOFENG CHEN, YAO XIAO, JINGXIN LEI
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China
Correspondence to: Jingxin Lei; e-mail: firstname.lastname@example.org.
Received: May 30, 2016
Accepted: August 3, 2016
Castor oil-derived decanediamide, as a novel ﬂexible epoxy curing agent, was synthesized by esterization with
methanol and ammonolysis with ammonia. The chemical structure and thermal properties of this novel curing agent were con-
ﬁrmed by Fourier transform infrared spectroscopy (FT-IR),
H nuclear magnetic resonance (
H NMR) analysis, differential scanning
calorimeter (DSC), and thermogravimetric analysis (TGA). The tensile strength, impact strength, dynamic mechanical properties,
and thermal stability of cured epoxy resin were investigated by tensile tests,dynamic mechanical analysis (DMA), and TGA, respec-
tively. The results showed that the prepared decanediamide had a high yield of 85.4%, and the epoxy resin cured by the decanedi-
amide revealed a slight decrease in the mechanical properties and thermal stability, and a longer pot life at high temperature
compared with that of a conventional epoxy curing agent. Asphalt as a toughening agent was added into this system, in order to
improve the poor brittle resistance of pure epoxy resin, which proved to have good compatibility with this system and improve
the brittle resistance effectively. Thus, the decanediamide has a great potential to replace some of current petroleum-based com-
pounds in the synthesis of epoxy curing agents. © 2016 Wiley Periodicals, Inc. Adv Polym Technol 2018, 37, 21760; View this arti-
cle online at wileyonlinelibrary.com. DOI 10.1002/adv.21760
Asphalt, Castor oil, Decanediamide, Flexible epoxy curing agent
olymer materials derived from renewable resources,
especially vegetable oils have drawn much attention due
to their low cost, environmental friendliness, and societal
advantages over the recent years.
dicarboxylic acids were often obtained by the hydrolysis, oxi-
dation of chain scission, or splitting of vegetable oils.
oil derived from vegetable oils is a low-cost, abundantly avail-
able, renewable raw material that enables them to be used in
a wide range of applications.
Castor oil is an abundantly
available natural material composed of more than 80% castor
acid and circa 20% neutral compounds.
Sebacic acid was
prepared by the thermal cracking of castor oil on the catalyst
of alkali. Sebacic acid and its derivatives are widely used in
the ﬁelds of plasticizers, additives, spices, coatings, and
Owing to the friendly raw materials easily obtained,
sebacic acid and its derivatives were considered for preparing
the epoxy curing agent. Irreversible changes in epoxy resin
occur during the curing process and the curing reaction rate
depends on the kinds of epoxy curing agents. The curing reac-
tion rate and properties of epoxy resins are dependent on the
chemical structure and molecular weight of the curing agents.
If the chemical structures of cured epoxy resins are made up
of aromatic rings, heterocyclic rings, or ladder structure, their
thermal resistance is superior to those constituents with ali-
Epoxy curing agents are usually divided
into amine curing agents, alkali curing agents, anhydride
agents, and catalytic curing agents according to their func-
In our recent researches, we synthesized a
novel castor oil-derived decanediamide which could be used
as a ﬂexible curing agent for epoxy curing. Compared with
traditional epoxy curing agent, the castor oil-derived decane-
diamide offers long pot life at high temperature which will
have special potential applications.
However, the highly cross-linked epoxy resins are brittle
and have poor crack resistance, which limit their applica-
Therefore, over the past few decades, the modiﬁca-
tion of epoxy resins to improve their physical and mechanical
properties has been an active area of research. Many methods
have been developed, such as modifying with an additional
usage of ﬂexible curing agents,
trating networks with thermoplastics.
Among these different
types of modiﬁcations, physical blending is one of the most
acceptable approaches. Asphalt as a petroleum-based material
was broadly used to modify epoxy resin by physical
Advances in Polymer Technology, Vol. 37, No. 4, 2018, DOI 10.1002/adv.21760
© 2016 Wiley Periodicals, Inc.
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