Effect of Carbon Nanotubes Content on the Structure and Photo-Oxidation Behaviors of Polypropylene

2011 ◽  
Vol 189-193 ◽  
pp. 1222-1227 ◽  
Author(s):  
Yuan Lian ◽  
Hong Mei Wang ◽  
Dian Wu Huang
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Tests ◽  
Oxidation Time ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Photo Oxidation ◽  
Twin Screw ◽  
Multi Walled Carbon Nanotubes ◽  
Carbonyl Formation ◽  
Walled Carbon Nanotubes

Polypropylene (PP) nanocomposites with 0.1, 0.2, 0.5, 0.8, 1.0 and 2.0 wt% multi-walled carbon nanotubes (MW-CNTs) were prepared via meltcompounding in a twin-screw extruder followed by injection molding. The effects of MW-CNTs additions on the structure, mechanical and photo-oxidation behavior of PP were studied using X-ray diffraction (XRD), differential scanning calorimetry (DSC), tensile tests and FT-IR apparatus. XRD results showed that only α-PP crystals form in the PP/MW-CNTs composites. DSC results confirmed that the corporation of MW-CNTs enhanced the nucleation process on PP crystallization. Results of the tensile tests showed that before photo-oxidation, the tensile strengths of the samples increased with the increase of MW-CNTs contents when the MW-CNTs contents were less than 1% wt, whilst the tensile strength decreased at higher MW-CNTs contents (>1% wt). When subjected to photo-oxidation, the tensile strengths of the samples decreased with the increasing photo-oxidation time. The resistance to accelerated photo-oxidation of PP/MW-CNTs composites was also compared with the photo-oxidation behaviour of the original polypropylene sample. At short photo-oxidation time, such as under 250 h, the rates of carbonyl formation for the PP/MW-CNTs composites are similar to that observed for the original polypropylene but at longer photo-oxidation times the carbonyl formation increases for lower MW-CNTs contents (0.1, 0.2, 0.5 and 0.8% wt), and decreases for higher MW-CNTs contents (1 and 2% wt). It was found that the MW-CNTs showed both anti-degradation and pro-degradation effects at different concentrations.

Cure and Dynamic-Mechanical Behaviors of Vinyl Ester Resinfilled with Multi-Walled Carbon Nanotubes

2010 ◽  
Vol 150-151 ◽  
pp. 1413-1416 ◽  
Author(s):  
Hong Yan Chen ◽  
Zhen Xing Kong ◽  
Ji Hui Wang
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Ester ◽  
Mechanical Response ◽  
Cure Kinetics ◽  
Crosslinking Density ◽  
Vinyl Ester Resin ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

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.

scholarly journals Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes

2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.

Compression Moulding of Thermoplastic Nanocomposites Filled with MWCNT

2017 ◽  
Vol 25 (8) ◽  
pp. 611-620 ◽  
Author(s):  
Fabrizio Quadrini ◽  
Denise Bellisario ◽  
Loredana Santo ◽  
Felicia Stan ◽  
Fetecau Catalin
Keyword(s):  
Carbon Nanotubes ◽  
Differential Scanning Calorimetry ◽  
Filler Content ◽  
Thermoplastic Polyurethane ◽  
Mechanical Tests ◽  
Compression Moulding ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon-nanotubes (MWCNTs) were melt-mixed with three different thermoplastic matrices (polypropylene, PP, polycarbonate, PC, and thermoplastic polyurethane, TPU) to produce nanocomposites with three different filler contents (1, 3, and 5 wt.%). Initial nanocomposite blends (in the shape of pellets) were tested under differential scanning calorimetry to evaluate the effect of the melt mixing stage. Nanocomposite samples were produced by compression moulding in a laboratory-scale system, and were tested with quasi-static (bending, indentation), and dynamic mechanical tests as well as with friction tests. The results showed the effect of the filler content on the mechanical and functional properties of the nanocomposites. Compression moulding appeared to be a valuable solution to manufacture thermoplastic nanocomposites when injection moulding leads to loss of performance. MWCNT-filled thermoplastics could be used also for structural and functional uses despite, the present predominance of electrical applications.

scholarly journals Optimization of sulfate removal from wastewater using magnetic multi-walled carbon nanotubes by response surface methodology

2017 ◽  
Vol 76 (10) ◽  
pp. 2593-2602 ◽  
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Sedighi ◽  
Ehsan Jabbari
Keyword(s):  
Carbon Nanotubes ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Polynomial Equation ◽  
X Ray Diffraction ◽  
Adsorption Models ◽  
Sulfate Removal ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Abstract This paper reports a facile method for removal of sulfate from wastewater by magnetic multi-walled carbon nanotubes (MMWCNTs). Multi-walled carbon nanotubes and MMWCNTs were characterized by X-ray diffraction, Raman, transmission electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results of the analysis indicated that MMWCNTs were synthesized successfully. The MMWCNTs can be easily manipulated in a magnetic field for the desired separation, leading to the removal of sulfate from wastewater. Response surface methodology (RSM) coupled with central composite design was applied to evaluate the effects of D/C (adsorbent dosage per initial concentration of pollutant (mgadsorbent/(mg/l)initial)) and pH on sulfate removal (%). Using RSM methodology, a quadratic polynomial equation was obtained, for removal of sulfate, by multiple regression analysis. The optimum combination for maximum sulfate removal of 93.28% was pH = 5.96 and D/C = 24.35. The experimental data were evaluated by the Langmuir and Freundlich adsorption models. The adsorption capacity of sulfate in the studied concentration range was 56.94 (mg/g). It was found out that the MMWCNTs could be considered as a promising adsorbent for the removal of sulfate from wastewater.

Synthesis and Characterization of Nitrogen Doped Carbon Nanotubes

2010 ◽  
Vol 636-637 ◽  
pp. 714-721 ◽  
Author(s):  
K. Kordatos ◽  
A. Ntziouni ◽  
A. Theodoratou ◽  
Maria Perraki ◽  
M. Terrones ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Production Method ◽  
X Ray Diffraction ◽  
Nitrogen Doped ◽  
Solid Mixture ◽  
Multi Walled Carbon Nanotubes ◽  
Metallic Catalyst ◽  
Nitrogen Doped Carbon ◽  
Walled Carbon Nanotubes

The present work describes the synthesis of nitrogen doped multi-walled carbon nanotubes (CNx CNT). The chosen production method was the catalytic pyrolysis of a solid mixture containing [Ni(DMG)2] and melamine (C3H6N6), under an Αr atmosphere. A series of various experiments were performed, using different proportions of the reaction mixture, in order to optimize the production conditions of nitrogen doped carbon nanotubes. Finally, the produced materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), Raman spectroscopy as well as thermogravimetric analysis (TGA). The obtained data from all the above analyses, showed the formation of nitrogen doped carbon nanotubes of various diameters as well as nanofibers surrounded by byproducts such as aggregations of amorphous carbon and metallic catalyst, depending on the proportion of the reaction mixture.

scholarly journals Structure and Mechanical Properties of Multi-Walled Carbon Nanotubes-Filled Isotactic Polypropylene Composites Treated by Pressurization at Different Rates

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1294 ◽  
Author(s):  
Xiaoting Li ◽  
Wenxia Jia ◽  
Beibei Dong ◽  
Huan Yuan ◽  
Fengmei Su ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Isotactic Polypropylene ◽  
Mechanical Tests ◽  
High Yield ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polypropylene Composites ◽  
Pressurization Rate ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Isotactic polypropylene filled with 1 wt.% multi-walled carbon nanotubes (iPP/MWCNTs) were prepared, and their crystallization behavior induced by pressurizing to 2.0 GPa with adjustable rates from 2.5 to 1.3 × 104 MPa/s was studied. The obtained samples were characterized by combining wide angle X-ray diffraction, small angle X-ray scattering, differential scanning calorimetry, transmission electron microscopy and atomic force microscopy techniques. It was found that pressurization is a simple way to prepare iPP/MWCNTs composites in mesophase, γ-phase, or their blends. Two threshold pressurization rates marked as R1 and R2 were identified, while R1 corresponds to the onset of mesomorphic iPP formation. When the pressurization rate is lower than R1 only γ-phase generates, with its increasing mesophase begins to generate and coexist with γ-phase, and if it exceeds R2 only mesophase can generate. When iPP/MWCNTs crystallized in γ-phase, compared with the neat iPP, the existence of MWCNTs can promote the nucleation of γ-phase, leading to the formation of γ-crystal with thicker lamellae. If iPP/MWCNTs solidified in mesophase, MWCNTs can decrease the growth rate of the nodular structure, leading to the formation of mesophase with smaller nodular domains (about 9.4 nm). Mechanical tests reveal that, γ-iPP/MWCNTs composites prepared by slow pressurization display high Young’s modulus, high yield strength and high elongation at break, and meso-iPP/MWCNTs samples have excellent deformability because of the existence of nodular morphology. In this sense, the pressurization method is proved to be an efficient approach to regulate the crystalline structure and the properties of iPP/MWCNTs composites.

The Impact of Nanomaterials on Fabrication Silicon Solar Cells by Pulsed Laser Deposition

2020 ◽  
Vol 30 ◽  
pp. 41-54
Author(s):  
Shelan A. Farman ◽  
Muayed K. Ibrahim ◽  
Kadhim A. Aadim
Keyword(s):  
Carbon Nanotubes ◽  
Solar Cells ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Si Solar Cells ◽  
Multi Walled Carbon Nanotubes ◽  
Uv Visible ◽  
Walled Carbon Nanotubes ◽  
The Impact

Nanocarbon structures such as graphene (GR), single-walled carbon nanotubes (SWCNTs) as well as the multi-walled carbon nanotubes (MWCNTs) were deposited on crystalline n-type silicon wafers to fabricate nanoCarbon-Si solar cells. Nanocarbon films deposited on glass and porous silicon (PS) via pulse laser deposition (PLD) with the use of Q-Switching Nd: YAG laser with λ=1064 (nm), Energy (E)=700 (mJ), Repetition rate (f)=6 (HZ) under vacuum condition with 2.5×10-2 (mbar). The surface morphology, structure, and optical Nanocarbon thin films have been examined with the use of X-ray Diffraction (XRD), Atomic force microscope (AFM), FTIR spectrophotometer and UV-visible. In addition, the power conversion efficiency that is related to the prepared solar cells is estimated through J-V characterization. The PCE of all Nanocarbon/PS follows the orders; SWCNTs/PS < MWCNTs/PS< GR/PS.

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