Epoxy shape‐memory polymer reinforced by thermally reduced graphite oxide: Influence of processing techniques

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In this study, epoxy shape-memory polymer (ESMP) was infiltrated into the scaffolds of vertically aligned carbon nanotubes (CNTs) array grown by chemical vapor deposition (CVD). In the fabricated CNTs array/ESMP nanocomposite, the CNTs interconnected with each other and a three-dimensional (3D) network of the CNTs was formed. As a result, both thermal conductivity and electrical conductivity of the CNTs array/ESMP nanocomposite were higher than the random CNTs/ESMP composite fabricated by conventional high-speed mechanical stirring. In the random CNTs/ESMP composite, the CNTs aggregated seriously in the matrix. Along the CNTs axis, The CNTs array/ESMP nanocomposite showed a higher modulus and hardness than the random CNTs/ESMP composite, as revealed by nanoindentation tests. Under microwave radiation, the temperature of the CNTs array/ESMP nanocomposite increased more rapidly than pristine ESMP and the random CNTs/ESMP composite. Consequently, the CNTs array/ESMP nanocomposite showed a faster shape recovery speed compared with pristine ESMP and the random CNTs/ESMP composite in their microwavetriggered shape memory behaviors. Especially, the CNTs array/ESMP nanocomposite can recover the deformation fully in response to as low as 60 W microwaves. The presented CNTs array/ESMP nanocomposite with improved mechanical property and fast responses to low-power microwaves may find potential applications in smart devices.

“…The fixed bending angle ( θ f ) was measured. Shape fixity ratio ( R f ) of the specimen can be calculated by:

R_{f} = \frac{θ_{normalf}}{180^{°}} \times 100 %

…”

Section: Methodsmentioning

confidence: 99%

Carbon nanotubes array reinforced shape‐memory epoxy with fast responses to low‐power microwaves

Chen

Xiao-pei

et al. 2019

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“…Carboxylic acid functionalized MWCNTs (MWCNT‐COOH, the COOH content: 3.86 wt %) and graphene nanoplatelets (GNPs) (thickness 4–20 nm, diameter 5–10 µm) were purchased from Chengdu Organic Chemistry Co. Ltd. of China. Functionalized graphene sheets (FGSs) were synthesized by exfoliating graphite oxide at 500 °C …”

Section: Methodsmentioning

confidence: 99%

Microwave responsive epoxy nanocomposites reinforced by carbon nanomaterials of different dimensions

Chen

Liu

Leng

2017

Self Cite

This study fabricated nanocomposites consisting of epoxy-based shape memory polymer (ESMP) matrix and carbon nanofillers. The nanofillers include zero-dimensional carbon black, one-dimensional multiwalled carbon nanotubes, two-dimensional (2D) graphene nanoplatelets, and three-dimensional (3D) functionalized graphene sheets, which are all efficient microwave-absorbing materials that can transform microwaves into heat energy. As a result, the temperatures of the nanocomposites increased more rapidly than pristine ESMP in microwaves. The functionalized graphene sheets were found to transform the microwaves into heat more efficiently than the other nanofillers. Possible microwave propagation paths in the nanocomposites were proposed. Moreover, the nanocomposites displayed significantly higher mechanical strengths than pristine ESMP. The low cost and strong nanocomposites with fast microwave responses may be applied as actuators or deployable devices in medical treatments. V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45676.

“…The results showed that the tensile strength of fluorinated MWCNT/epoxy composites increased by 31%, compared with the untreated MWCNT/epoxy composites. In a different study, it was found that, with the addition of 1.0 wt % graphene oxide to epoxy shape‐memory polymer, the tensile strength and Young's modulus were increased by 38.1–44.1% and 36.4–41.1%, respectively. Chatterjee et al .…”

Section: Introductionmentioning

confidence: 99%

Effects of variation of steric repulsion between multiwall carbon nanotubes and anionic surfactant in epoxy nanocomposites

Sumdani

Islam

Yahaya

2018

The aim of this research is to investigate the effects of the variation of the steric repulsion force among multiwalled carbon nanotubes (MWCNTs) while dispersed in epoxy. Different amounts (0.25, 0.5, and 0.75 wt %) of MWCNTs were used to prepare nanocomposites in the presence of an anionic surfactant, linear alkyl benzene sulfonic acid (LABSA), to examine the effect of loading MWCNTs into the epoxy composites. The mechanical properties of the nanocomposites were analyzed by tensile, flexural, and impact testing. The structural and crystalline properties were evaluated by Fourier transform infrared spectroscopy and X‐ray diffraction analysis. The thermal properties were assessed by thermogravimetric analysis and differential scanning calorimetry, whereas dispersion and surface morphology were examined by scanning electron microscopy. It was observed that MWCNTs enhanced the tensile strength (TS) and flexural strength (FS) of the composites. The TS and FS of the composites were improved by 75.0% and 91.6%, respectively, with the inclusion of 0.50 wt % MWCNTs. The thermal properties of the composites were enhanced significantly with the addition of MWCNTs. LABSA improved the steric repulsion of MWCNTs as a consequence of homogeneous dispersion in the composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46883.