Controllable design of nanostructure in block copolymer reinforced
Zhengguang Heng , Haoruo Zhang, Yang Chen , Huawei Zou, Mei Liang
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065,
Correspondence to: H. Zou (E-mail: email@example.com) and Y. Chen (E-mail: firstname.lastname@example.org)
The modification of epoxy composites through the construction of nanostructures via the self-organization of block
copolymers in epoxy has become a hot topic. In this research, polystyrene-b-poly(E-caprolactone)-b-polydimethylsiloxane-b-poly(E-
caprolactone)-b-polystyrene (PS-PCL-PDMS-PCL-PS) block copolymers with different lengths of PS subchains were synthesized and
incorporated into epoxy thermoset. Due to the difference in the length of PS subchains, two different sizes of core-shell nanostruc-
tures were obtained. When these two block copolymers were incorporated into epoxy, the tensile strength, elongation at break, damp-
ing temperature in range (tan d > 0.2), and storage modulus of the epoxy thermoset below 105 8C were simultaneously improved.
Meanwhile, the effects of the lengths of PS subchains on the size of nanostructures and the relationship between microstructure and
macroscopic properties of epoxy composites were systematically investigated.
2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135,
block copolymer; epoxy thermoset; macroscopic properties; microstructure; nanostructure design
Received 18 October 2017; accepted 11 February 2018
Over the past decades, incorporating nanostructure into compo-
sites to fabricate high-performance materials has drawn consid-
erable attention. Experiments showed that nanostructure in
epoxy confers some unique features to polymer composites,
such as reinforcement, toughening, and functionalization.
Generally, the efficiency of reinforcing fillers in composites is
directly proportional to the filler surface area to volume ratio
while inversely proportional to the size. Various experiments
have demonstrated that incorporating nanoparticles, which
means increasing interfacial area, could promote the transmis-
sion of stress in the matrix leading to significantly improve the
strength, stiffness, and Young’s modulus of composites, when
compared to macroparticles.
So far, various kinds of nanofillers are utilized to modify epoxy
studies the tensile properties of epoxy nano-
composites filled with 10 wt % barium titanate (500 nm), the
results show that modulus of elasticity and breaking stress of
nanocomposites were almost 80% and 38.6% improved, com-
pared with the neat epoxy, respectively. Epoxy resin nanocom-
posites reinforced with core-shell structured magnetic Ni@NiO
nanoparticles are fabricated by Wang,
the 5 wt % Ni@NiO/EP
nanocomposites exhibits 37.8% and 16.3% increase in hardness
and elastic modulus, respectively. An investigation about
montmorillonite clay modified epoxy demonstrates 31.6%
improvement in modulus and 27% improvement in strength
with an addition of 2 wt % of clay.
Although, the incorpora-
tion of nanostructure has been evidenced to be a successful way
to reinforce epoxy thermoset, several drawbacks, such as the
dispersity of nanofillers, high cost, high viscosity, and so on,
restrict their use to the extent, where instead their full potential
could be exploited.
Fortunately, owing to the difference in solubility parameter
among segments of the block copolymer and epoxy, block
copolymer can self-organize into regular and ordered nano-
structures in epoxy matrix. The disadvantages of high viscosity
and poor dispersity could be considerably avoided due to the
presence of epoxy miscible subchains in block copolymer.
Besides, the structures, morphologies, and sizes of the nano-
structures can be flexibly designed by changing the components
and molecular weight of block copolymer. When thermoset res-
ins acts as selective solvent, amphiphilic block copolymers will
self-organize into nanostructures following two mechanisms:
and reaction-induced microphase separation
So far, various morphologies, such as spherical,
worm-like micelles, hexagonally packed cylinders, bilayer
micelles, or mixtures of them, have been obtained.
the studies focus on the formation mechanisms and
2018 Wiley Periodicals, Inc.
J. APPL. POLYM. SCI. 2018, DOI: 10.1002/APP.46362
46362 (1 of 9)