One-Step Preparation of Non-Covalent Functionalized
Carboxylic Multi-Walled Carbon Nanotubes/Polymethyl
Methacrylate Nanocomposites Via In Situ Polymerization
YU JIANG, XIANG WANG, ZONGZHI YU, JUNPING ZHENG
Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin
Correspondence to: Junping Zheng; e-mail: email@example.com.
Received: February 22, 2016
Accepted: July 7, 2016
In this work, methyl methacrylate (MMA) copolymerized with cationic monomer 2-(methacryloyloxy)ethyltri-
methylammonium chloride (MTC) via in situ suspension copolymerization, meanwhile, negatively charged carboxylic multi-walled
carbon nanotubes (MWCNTs) were adsorbed through electrostatic interactions during copolymerization process to fabricate
nanocomposites. The chemical structure of copolymer was analyzed by
H nuclear magnetic resonance (
H-NMR). The interfacial
adhesion between MWCNTs and polymer matrix was characterized by Fourier transform infrared spectroscopy (FTIR) and scan-
ning electron microscopy (SEM). The morphologies of synthesized microspheres were observed by SEM. Finally, the mechanical
properties of nanocomposites were investigated in detail. The results suggest that: the nanocomposites have been successfully syn-
thesized by in situ suspension copolymerization; both the dispersion of MWCNTs and interfacial adhesion between MWCNTs and
matrix were improved; and the mechanical properties of nanocomposites were dramatically reinforced. The nanocomposites were
prepared in one step without additional treatments of MWCNTs or copolymer matrix, which makes the method relatively efﬁcient.
© 2016 Wiley Periodicals, Inc. Adv Polym Technol 2018, 37, 21749; View this article online at wileyonlinelibrary.com. DOI
Interfaces, Mechanical properties, Nanocomposites
s carbon nanotubes (CNTs) were discovered by Iijima in
a multitude of studies concerning them have been
conducted due to their high aspect ratio, low mass density as
well as superior mechanical, thermal, electrical, and magnetic
properties. For many years, CNTs have been widely utilized
in polymer matrix composites as reinforcements.
nately, strong tube-tube van der Waals force can easily induce
CNTs to entangle and agglomerate, which makes CNTs hard
to disperse uniformly in polymer matrix. In order to solve this
issue, a host of techniques have been developed. One of the
most widely used methods is covalent functionalization,
meaning modiﬁers react with CNTs and connect themselves
to the surface of CNTs by covalent bonds. Compared with
original CNTs, covalently functionalized CNTs exhibit far
more excellent compatibility with polymer, which contributes
to inhibiting the agglomeration of CNTs and enhancing the
interface adhesion between CNTs and polymer matrices.
However, a notable drawback of covalent functionalization is
the disruption of the extended p conjugation in nanotubes,
which may result in the deterioration of mechanical and ther-
mal properties of the original CNTs.
Alternatively, the method of non-covalent functionalization
conserves the conjugated system of the CNTs sidewalls, and
therefore it does not affect the ﬁnal structural properties of the
Non-covalent functionalization mainly includes sur-
factant adsorption and polymer wrapping, etc., which utilizes
non-covalent interactions such as p-p interactions, electrostatic
interactions, hydrophobic attractions, hydrogen bond, and van
der Waals force.
For example, Geng et al. selected poly-
oxyethylene octyl phenyl ether as a modiﬁer to attach the sur-
faces of CNTs by hydrophobic attractions and the achieved
mixtures were then mixed with epoxy resin to prepare
nanocomposites with enhanced mechanical properties.
et al. utilized 4-aminomethyl pyridine modiﬁed poly(methyl
methacrylate-co-methacrylic acid) to wrap CNTs through p-p
interactions and prepared polymethyl methacrylate (PMMA)/
CNTs nanocomposites with improved dispersion and excellent
properties by melt mixing.
Although there are quite a few
examples of preparing CNTs/polymer nanocomposites
through non-covalent interactions in the open literature, it is a
remarkable fact that previous preparation techniques involve
Advances in Polymer Technology, Vol. 37, No. 4, 2018, DOI 10.1002/adv.21749
© 2016 Wiley Periodicals, Inc.
21749 (1 of 8)