Effects of Carbon Nanotube Functionalization on the Mechanical Properties of Vinyl Ester Composites

2011 ◽  
Vol 233-235 ◽  
pp. 2315-2318 ◽  
Author(s):  
Hong Yan Chen ◽  
Hua Bo Huang ◽  
Ji Hui Wang

Chemically functionalized muliti-walled carbon nanotubes (MWCNTs)/vinyl ester resin (VE) nanocomposites were prepared. MWCNTs were first treated by H2SO4/HNO3 acid mixture, and then carboxylated MWCNTs were grafted of methacrylic acid glycidyl ester (GMA). Raman microscopy and Fourier transform infrared spectroscopy (FT-IR) analyses proved the effectivenss of acid-treatment and chemical functionalization. Furthermore, chemical functionalization did not greatly disrupt carbon nanotubes structure and Transmission electron microscopy (TEM) showed that there was a GMA thin layer on the MWCNTs surface, which contributes to the homogenous dispersion of MWCNTs in vinyl ester resin matrix and the CNTs-VE interfacial interaction. Thus the nanocomposites containing MWCNT-GMA possess larger storage modulus values as well as higher glass transition temperatures (Tg).

2010 ◽  
Vol 150-151 ◽  
pp. 1413-1416 ◽  
Author(s):  
Hong Yan Chen ◽  
Zhen Xing Kong ◽  
Ji Hui Wang

The cure kinetics of Derakane 411-350, a kind of vinyl ester resin, and its suspensions containing multi-walled carbon nanotubes( MWCNTs) were investigated via non-isothermal dynamic scanning calorimetry (DSC) measurements. The results showed that incorporation of MWCNTs into vinyl ester resin excessively reduces polymerization degree and crosslinking density of vinyl ester resin. For suppressing the negative effect caused by nanotubes, the higher temperature initiator combined with the initiator MEKP was used. Dynamic-mechanical Behavior testing was then carried out on the cured sample in order to relate the curing behavior of MWCNTs modified resin suspensions to mechanical response of their resulting nanocomposites. It was revealed that nanocomposites containing MWCNTs possessed larger storage modulus values as well as higher glass transition temperatures (Tg) as compared to those without MWCNTs after using mixed intiators system to improve the degree of cure.


2015 ◽  
Vol 19 (04) ◽  
pp. 622-630 ◽  
Author(s):  
Saeed Rayati ◽  
Zahra Sheybanifard

In the present work, oxidation of alkenes with hydrogen peroxide in the presence of meso-tetrakis(4-hydroxyphenyl)porphyrinatoiron(III) chloride supported onto surface of functionalized multi-wall carbon nanotubes (FMWCNT), [ Fe ( THPP ) Cl@MWCNT ], is reported. The simple heterogeneous catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and also thermal analysis. The amount of the catalyst loaded on the nanotubes was determined by atomic absorption spectroscopy. This heterogeneous catalyst proved to be an efficient and green catalyst and was successfully able to activate hydrogen peroxide without any additive toward the oxidation of alkenes in ethanol as a green solvent. Performance of the catalyst in oxidation of various alkenes was inspected under reflux, ultrasonic irradiation and mechanical stirring. Moreover, the catalyst can be reused several times under similar conditions.


NANO ◽  
2010 ◽  
Vol 05 (03) ◽  
pp. 139-142 ◽  
Author(s):  
ROSTAM MORADIAN ◽  
BANDAR ASTINCHAP

Multi-walled carbon nanotubes have been decorated by SnS2 nanoparticles with different sizes using a simple chemical method. In this work, first multi-walled carbon nanotubes (MWCNTs) functionalized by using acid mixture, then this system coated by tin disulfide ( SnS2 ) nanoparticles with nanoparticle sizes controlling. The samples have been characterized by X-Ray diffraction and transmission electron microscopy (TEM). We found size and uniformity of the SnS2 nanoparticles influenced by increasing reaction temperature and time. By increasing reaction temperature and time, size of the SnS2 nanoparticles became larger and nonuniform. Also we found that ultrasound waves could be used instead of organic compounds for avoiding agglomeration of the SnS2 nanoparticles on the surface of MWCNTs.


2007 ◽  
Vol 334-335 ◽  
pp. 797-800
Author(s):  
Peng Cheng Ma ◽  
Jang Kyo Kim ◽  
Ben Zhong Tang

This paper presents a method for chemical functionalization of CNTs through the combined process of UV/O3 treatment and silanization process. FT-IR and TEM were employed to characterize the changes in surface functionalities and morphology. The results indicate improved dispersion and attachment of silane molecules on the surface of CNTs. Epoxy matrix nanocomposites containing functionalized CNTs showed much better dispersion with associated higher mechanical properties than those without functionalization. These findings confirmed the improved interfacial interactions due to covalent bonding between the functionalized CNTs and epoxy resin.


2019 ◽  
Vol 56 (4) ◽  
pp. 735-743 ◽  
Author(s):  
Adrian Cotet ◽  
Marian Bastiurea ◽  
Gabriel Andrei ◽  
Alina Cantaragiu ◽  
Anton Hadar

Single walled carbon nanotubes (SWCNT) and multi walled carbon nanotubes (MWCNT)/ vinyl ester nanocomposites with three different contents of carbon nanotubes (CNTs) have been prepared by the simple melt-compounding method. A fine and homogeneous dispersion of CNTs throughout vinyl ester resin has been noticed by SEM images. Two mechanical tests (compression and three point bending test) show that, compared to neat vinyl ester resin, compression modulus and compression strength of the nanocomposites have been significantly improved by about 9% and 14%, respectively, when incorporating only 0.15 wt.% MWCNTs. Furthermore, thermal behavior of SWCNT and MWCNT/ vinyl ester nanocomposites has been investigated and discussed based on differential scanning calorimetry (DSC) and thermo- mechanical analysis (TMA). Glass transition temperature (Tg) and coefficient of thermal expansion (CTE) have been increased and decreased, respectively, with increasing of CNTs content.


2011 ◽  
Vol 312-315 ◽  
pp. 460-465 ◽  
Author(s):  
M. Chitsazzadeh ◽  
H. Shahverdi ◽  
Mahmood M. Shokrieh

Excellent physical and mechanical properties of carbon nanotubes (CNTs) make them outstanding candidate as fillers to fabricate multi-functional polymer composites. It is assumed that a high level of dispersion in the preparation stage may lead to a more effective nanocomposite. In this research, the dispersion state of multi-walled carbon nanotubes (MWNTs) at various contents in an unsaturated vinyl ester resin is investigated during fabrication by on-line monitoring the viscosity of suspensions as a function of sonication time and energy introduced. The results show that initial viscosities of suspensions increase by adding more MWNTs to the resin. The viscosities gradually increase during the sonication and reach to maximum values, when it is assumed that the dispersion is completed. After this step the viscosity subsequently decreases. The energy density required to achieve a good dispersion of MWNTs in vinyl ester is obtained. The qualities of dispersion in cured composites are characterized by examining the sections using the scanning electron microscope (SEM) to confirm the results of viscosity measurements. The stabilization of MWNTs is achieved by adding a commercial dispersant and stabilizer, BYK-P 104S, by 0.0375 wt% . The results indicate that adding more surfactant to the suspension makes it unstable and leads to flocculation. The stabilization of suspensions is investigated by using viscosity measurement. Also, FT-IR is used to determine the possible mechanism of surfactant to stabilize the MWNTs in vinyl ester.


2019 ◽  
Vol 73 (3) ◽  
pp. 183-196 ◽  
Author(s):  
Nevena Vukic ◽  
Ivan Ristic ◽  
Milena Marinovic-Cincovic ◽  
Radmila Radicevic ◽  
Branka Pilic ◽  
...  

This paper presents influence of the type of carbon nanotube functionalization on properties of poly(L-lactide) (PLLA) based nanocomposite materials. For this purpose surface modifications of multi-walled carbon nanotubes (MWCNTs) were performed by chemical and irradiation techniques, while thermo gravimetric analysis, UV-Visible and Fourier-transform infrared (FT-IR) spectroscopies confirmed successful covalent functionalization. Series of PLLA bionanocom-posites with different contents of functionalized MWCNTs (0.7; 1.6; 2.1 wt%), were synthesized via ring-opening solution polymerisation of L-lactide. FT-IR analysis confirmed that grafting of L-lactide, under controlled condition, is possible to perform starting from the surface of functionalized MWCNTs. From differential scanning calorimetry results it was concluded that even low contents of chemically and irradiation functionalized MWCNTs had a significant effect on thermal properties of the prepared nanocomposites, raising the values of melting and glass transition temperatures. Thermogravimetric analysis (TGA) has shown that the degradation onset temperature for composites with chemically functionalized MWCNTs, was much higher than that for the neat poly(L-lactide) sample and composites with irradiation functionalized MWCNTs. Morphology studies by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that poly(L-lactide) covered surfaces and separated functionalized MWCNTs. Good dispersion of carbon nanotubes in polymer matrix enabled conductivity of synthesized materials, as determined by conductivity tests.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.


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