scholarly journals Attaining Toughness and Reduced Electrical Percolation Thresholds in Bio-Based PA410 by Combined Addition of Bio-Based Thermoplastic Elastomers and CNTs

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3420
Author(s):  
Itziar Otaegi ◽  
Nora Aranburu ◽  
Gonzalo Guerrica-Echevarría
Keyword(s):  
Electrical Conductivity ◽  
Thermoplastic Elastomers ◽  
Electrical Percolation ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Electrical Percolation Threshold ◽  
Percolation Thresholds ◽  
Ductile Behavior ◽  
Walled Carbon Nanotubes ◽  
The Impact

Multi-walled carbon nanotubes (CNTs) were added to provide electrical conductivity to bio-based polymer blends with improved toughness (based on commercially available Pebax thermoplastic elastomers and bio-based polyamide 4,10). A preliminary study including three different Pebax grades was carried out to select the grade and the composition that would best improve the impact properties of PA410. Thus, tough multiphasic PA/Pebax/CNT nanocomposites (NCs) with enhanced electrical conductivity were obtained. The CNTs were added either: (1) in the form of pristine nanotubes or (2) in the form of a PA6-based masterbatch. Hence, PA410/Pebax/CNT ternary NCs and PA410/PA6/Pebax/CNT quaternary NCs were obtained, respectively, up to a CNT content of 1 wt%. The ternary and quaternary NCs both showed similar mechanical and electrical properties. The electrical percolation threshold decreased with respect to previously studied corresponding NCs without Pebax, i.e., PA410/CNT and PA410/PA6/CNT, due to the partial volume exclusion effect of Pebax over the CNTs that were dispersed mainly in the PA matrix; materials with percolation concentrations as low as 0.38 wt% were obtained. With respect to mechanical properties, contrary to the NCs without Pebax, all the PA/Pebax/CNT NCs showed a ductile behavior and impact strength values that were from three to five-fold higher than that of the pure PA410.

A new electroactive polymer based on carbon nanotubes and carbon grease as compliant electrodes for electroactive actuators

2017 ◽  
Vol 29 (7) ◽  
pp. 1520-1530 ◽  
Author(s):  
Agata Nicolau-Kuklińska ◽  
Paulina Latko-Durałek ◽  
Paulina Nakonieczna ◽  
Kamil Dydek ◽  
Anna Boczkowska ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
The Novel ◽  
Electrical Percolation ◽  
Multi Walled Carbon Nanotubes ◽  
Electrical Percolation Threshold ◽  
Conductive Fillers ◽  
Walled Carbon Nanotubes ◽  
Silicone Matrix ◽  
Compliant Electrodes

In this article, the novel type of dielectric elastomer made of polydimethylsiloxane, multi-walled carbon nanotubes, and carbon grease is presented. The aim of the study was the development of compliant electrodes with ability for large deformation under applied voltage. The largest deformation of 47% was obtained for electrodes made of 2 wt% of multi-walled carbon nanotubes and 20 wt% of carbon grease. Electrical conductivity achieved for this material was 4.8 S/m. Good dispersion of conductive fillers within silicone matrix was obtained by calendaring technique. It was found that electrical percolation threshold for the compound was below 0.05 wt%. The structure of the material and its mechanical properties were determined. It was described that both properties, electrical conductivity and stiffness of the nanocomposite, have a significant influence on the extent of the electrode deformation. Two actuator designs are presented as the examples of application of developed material.

Experimental Investigation of Morphological and Electrical Characteristics of PS/MWCNT Nanocomposite Films

2018 ◽  
Vol 915 ◽  
pp. 104-109
Author(s):  
Barış Demirbay ◽  
Şaziye Uğur
Keyword(s):  
Annealed Film ◽  
Nanocomposite Films ◽  
Electrical Characteristics ◽  
Liquid Form ◽  
Mwcnt Content ◽  
Electrical Percolation ◽  
Glass Substrates ◽  
Multi Walled Carbon Nanotubes ◽  
Electrical Percolation Threshold ◽  
Walled Carbon Nanotubes

Electrical characteristics and morphology of nanocomposite films composed of two different polystyrene (PS) latexes impregnated with multi-walled carbon nanotubes (MWCNT) in the range between 0 wt% and 20 wt% were assessed by considering photon transmission (UV-Vis) technique and electrical conductivity measurements. Emulsion polymerization technique was employed both to synthesize very fine PS particles dispersed in water and to tailor the sizes of the PS particles as 382 nm and 560 nm, respectively. PS/MWCNT nanocomposite films were obtained from the liquid form on glass substrates via drop-casting method and all they dried at 40 QUOTE C. Each dried sample was then annealed at varying temperatures between 100 QUOTE C and 250 QUOTE C for 10 min. The surface conductivity QUOTE of each annealed film at 250 QUOTE C was measured and was found to increase dramatically above a certain mass fraction of MWCNT content, QUOTE . Each set of PS/MWCNT nanocomposite film had a similar electrical percolation threshold of QUOTE =1.5 wt% as the MWCNT content and critical exponents of QUOTE were found to be 2.64 and 1.19 for 382 nm and 560 nm PS latex systems, respectively.

Mechanical and Electrical Properties of Natural Rubber/Carbon Nanotube Nanocomposites Prepared by Latex Compounding

2013 ◽  
Vol 664 ◽  
pp. 543-546 ◽  
Author(s):  
Onusa Saravari ◽  
Anyaporn Boonmahitthisud ◽  
Warittha Satitnaithum ◽  
Saowaroj Chuayjuljit
Keyword(s):  
Electrical Conductivity ◽  
Natural Rubber ◽  
Glass Mold ◽  
Elongation At Break ◽  
Tear Strength ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Latex Compounding ◽  
Very High

In this study, natural rubber (NR) nanocomposites containing different loadings of multi- walled carbon nanotubes (CNTs) (0.1-0.4 phr) were prepared by latex compounding. The as-prepared nanolatex composites were cast into 3-mm sheets on a glass mold and then cured at 80°C for 3 h. The obtained vulcanizates were evaluated for their mechanical properties (tensile properties, tear strength and hardness) and surface electrical resistivity. The results showed that the incorporation of CNTs at a very low loading can reinforce NR by enhancing the tensile strength (0.2 phr optimal), modulus at 300% strain (0.2 phr optimal), elongation at break (0.4 phr optimal), tear strength (0.4 phr optimal) and hardness (0.4 phr optimal) and also increase the electrical conductivity (0.2 phr optimal). The reinforcing effect of CNTs is primarily attributed to its very high aspect ratio and great specific surface area, whilst the electrical conductivity of the nanocomposites is due to the formation of a continuous conductive network of CNTs in the NR matrix.

scholarly journals Influence of Carbon Nanotube-Pretreatment on the Properties of Polydimethylsiloxane/Carbon Nanotube-Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1355
Author(s):  
Astrid Diekmann ◽  
Marvin C. V. Omelan ◽  
Ulrich Giese
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Mechanical Performance ◽  
Softening Effect ◽  
Electrical Percolation ◽  
Optimum Parameters ◽  
Lauryl Ether ◽  
Solvent Residues ◽  
Electrical Percolation Threshold ◽  
Filler Dispersion

Incorporating nanofillers into elastomers leads to composites with an enormous potential regarding their properties. Unfortunately, nanofillers tend to form agglomerates inhibiting adequate filler dispersion. Therefore, different carbon nanotube (CNT) pretreatment methods were analyzed in this study to enhance the filler dispersion in polydimethylsiloxane (PDMS)/CNT-composites. By pre-dispersing CNTs in solvents an increase in electrical conductivity could be observed within the sequence of tetrahydrofuran (THF) > acetone > chloroform. Optimization of the pre-dispersion step results in an AC conductivity of 3.2 × 10−4 S/cm at 1 Hz and 0.5 wt.% of CNTs and the electrical percolation threshold is decreased to 0.1 wt.% of CNTs. Optimum parameters imply the use of an ultrasonic finger for 60 min in THF. However, solvent residues cause a softening effect deteriorating the mechanical performance of these composites. Concerning the pretreatment of CNTs by physical functionalization, the use of surfactants (sodium dodecylbenzenesulfonate (SDBS) and polyoxyethylene lauryl ether (“Brij35”)) leads to no improvement, neither in electrical conductivity nor in mechanical properties. Chemical functionalization enhances the compatibility of PDMS and CNT but damages the carbon nanotubes due to the oxidation process so that the improvement in conductivity and reinforcement is superimposed by the CNT damage even for mild oxidation conditions.

Electrical conductivity and rheological properties of carbon black based conductive polymer composites prior to and after annealing

2021 ◽  
pp. 096739112110012
Author(s):  
Qingsen Gao ◽  
Jingguang Liu ◽  
Xianhu Liu
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Rheological Properties ◽  
Network Formation ◽  
Loss Modulus ◽  
Conductive Polymer ◽  
Complex Viscosity ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.

scholarly journals Enhancement of Electrical Conductivity of Aluminum-Based Nanocomposite Produced by Spark Plasma Sintering

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1150
Author(s):  
Nicolás A. Ulloa-Castillo ◽  
Roberto Hernández-Maya ◽  
Jorge Islas-Urbano ◽  
Oscar Martínez-Romero ◽  
Emmanuel Segura-Cárdenas ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Spark Plasma Sintering ◽  
Experimental Tests ◽  
Powder Morphology ◽  
Plasma Sintering ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Ball Milling Technique ◽  
Walled Carbon Nanotubes

This article focuses on exploring how the electrical conductivity and densification properties of metallic samples made from aluminum (Al) powders reinforced with 0.5 wt % concentration of multi-walled carbon nanotubes (MWCNTs) and consolidated through spark plasma sintering (SPS) process are affected by the carbon nanotubes dispersion and the Al particles morphology. Experimental characterization tests performed by scanning electron microscopy (SEM) and by energy dispersive spectroscopy (EDS) show that the MWCNTs were uniformly ball-milled and dispersed in the Al surface particles, and undesirable phases were not observed in X-ray diffraction measurements. Furthermore, high densification parts and an improvement of about 40% in the electrical conductivity values were confirmed via experimental tests performed on the produced sintered samples. These results elucidate that modifying the powder morphology using the ball-milling technique to bond carbon nanotubes into the Al surface particles aids the ability to obtain highly dense parts with increasing electrical conductivity properties.

scholarly journals Fabrication of carbon nanotube-reinforced mortar specimens: evaluation of mechanical and pressure-sensitive properties

2018 ◽  
Vol 188 ◽  
pp. 01019 ◽  
Author(s):  
Evangelia K. Karaxi ◽  
Irene A. Kanellopoulou ◽  
Anna Karatza ◽  
Ioannis A. Kartsonakis ◽  
Costas A. Charitidis
Keyword(s):  
Cementitious Composites ◽  
Mixing Process ◽  
Mechanical And Electrical Properties ◽  
Pressure Sensitive ◽  
Polar Media ◽  
Significant Research ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Based Nanomaterials ◽  
Walled Carbon Nanotubes ◽  
Carbon Based

Carbon-based nanomaterials are promising reinforcing elements for the development of “smart” self-sensing cementitious composites due to their exceptional mechanical and electrical properties. Significant research efforts have been committed on the synthesis of cement-based composite materials reinforced with carbonaceous nanostructures, covering every aspect of the production process (type of nanomaterial, mixing process, electrode type, measurement methods etc.). In this study, the aim is to develop a well-defined repeatable procedure for the fabrication as well as the evaluation of pressure-sensitive properties of intrinsically self-sensing cementitious composites incorporating carbon- based nanomaterials. Highly functionalized multi-walled carbon nanotubes with increased dispersibility in polar media were used in the development of advanced reinforced mortar specimens which increased their mechanical properties and provided repeatable pressure-sensitive properties.

scholarly journals Synthesis, Characterization and Study of DC Electrical Conductivity of Poly[MWCNT/Imidoselenium] Composite

2019 ◽  
Author(s):  
Abeer O. Obeid ◽  
Fatma Al-Yusufy ◽  
Sama A Al-Aghbari ◽  
omar alshujaa ◽  
Yassin Gaber ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Selenium Dioxide ◽  
Chemical Functionalization ◽  
Dc Electrical Conductivity ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

<p>The chemical functionalization of amino multi-walled carbon nanotubes (MWCNT-NH<sub>2</sub>) by selenium dioxide (SeO<sub>2</sub>) was used to produce Poly [MWCNT/Imidoselenium] composite. The prepared poly-composite was characterized by FTIR, SEM, TEM, XRD, UV, DSC and TGA. The DC electrical conductivity of poly-composite was 4.3×10<sup>-4</sup> S/cm due to the interaction between the nanotubes. </p>

scholarly journals Accelerated Shape Forming and Recovering, Induction, and Release of Adhesiveness of Conductive Carbon Nanotube/Epoxy Composites by Joule Heating

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1030 ◽  
Author(s):  
Petr Slobodian ◽  
Pavel Riha ◽  
Robert Olejnik ◽  
Jiri Matyas
Keyword(s):  
Carbon Nanotube ◽  
Joule Heating ◽  
Adhesive Bonding ◽  
Recovery Process ◽  
Epoxy Adhesive ◽  
Porous Network ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Dc Current ◽  
Walled Carbon Nanotubes

The versatile properties of a nanopaper consisting of a porous network of multi-walled carbon nanotubes were applied to enhance the mechanical and electrical properties of a thermosetting epoxy polymer. The embedded nanopaper proved useful both in the monitoring of the curing process of the epoxy resin by the self-regulating Joule heating and in the supervising of tensile deformations of the composite by detecting changes in its electrical resistance. When heated by Joule heating above its glass transition temperature, the embedded carbon nanotube nanopaper accelerated not only the modelling of the composites into various shapes, but also the shape recovery process, wherein the stress in the nanopaper was released and the shape of the composite reverted to its original configuration. Lastly, in comparison with its respective epoxy adhesive, the internally heated electro-conductive carbon nanotube nanopaper/epoxy composite not only substantially shortened curing time while retaining comparable strength of the adhesive bonding of the steel surfaces, but also enabled a release of such bonds by repeated application of DC current.

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