scholarly journals Structure-property-processing investigation of electrically conductive polypropylene nanocomposites

2018 ◽  
Vol 25 (6) ◽  
pp. 1177-1186 ◽  
Author(s):  
Radwan Dweiri ◽  
Hendra Suherman ◽  
Abu Bakar Sulong ◽  
Jafar F. Al-Sharab
Keyword(s):  
Composite Materials ◽  
Flexural Properties ◽  
Structure Property ◽  
Melt Mixing ◽  
Electrically Conductive ◽  
Carbon Allotrope ◽  
Exfoliated Graphene ◽  
Multi Walled Carbon Nanotubes ◽  
Internal Mixer ◽  
Walled Carbon Nanotubes

AbstractThis paper investigates the structure-property-processing correlations of electrically conductive polypropylene (PP) nanocomposites. The process parameters and fabrication techniques of PP-based composite materials were studied. Various structures of carbon allotrope-based materials, including synthetic graphite (SG), exfoliated graphene nanoplatelets (xGnP), multi-walled carbon nanotubes (MWCNTs) and carbon black (CB), were used to fabricate the PP-based nanocomposites. The nanocomposites were prepared by either direct melt mixing using an internal mixer or by ball milling of components before the melt mixing process. The electrical and flexural properties were measured. In order to understand the conductivity behavior, both in-plane and through-plane electrical conductivities were measured. The results showed that the incorporation of the xGnP into PP/60 wt.% SG composites resulted in a slight increase of the in-plane conductivities and had a minimal effect on the through-plane conductivities. The addition of MWCNTs and CB to the PP/SG/xGnP composites had a significant effect on the electrical properties and was more pronounced in the case of MWCNTs. The flexural properties of all samples were much lower than those of pure PP. The interface between the filler and the PP matrix and the morphology of the composite materials were observed from the fracture surfaces of the composites using scanning electron microscopy (SEM). In addition, SEM was employed to observe adhesion, microstructural homogeneity, orientation of the xGnP platelets and agglomeration in the composites.

Selective Dispersion of Multi-Walled Carbon Nanotubes in Segmented Polyurethane with Different Melt Mixing Process

2017 ◽  
Vol 730 ◽  
pp. 237-241
Author(s):  
Kittimon Jirakittidul ◽  
Krittaya Khrongsakun ◽  
Kannika Khongkhaw ◽  
Kusuman Nernplod
Keyword(s):  
Carbon Nanotubes ◽  
Soft Segment ◽  
Mixing Time ◽  
Melt Mixing ◽  
Segmented Polyurethane ◽  
Soft Segments ◽  
Multi Walled Carbon Nanotubes ◽  
Lcr Meter ◽  
Internal Mixer ◽  
Walled Carbon Nanotubes

Polyurethanes (PU) have been widely used in many applications since their properties can be tailored as desire. In order to improve their electrical property, PU is incorporated with multi-walled carbon nanotubes (MWCNT). The effects of different mixing times and temperatures on selective dispersion of MWCNT in segmented PU were studied. Furthermore, segmented PU based on two different soft segments; i.e. polyester (PU-ester) and polyether (PU-ether), were used. PU/MWCNT nanocomposites were prepared by an internal mixer for 4-12 minutes at 190-210°C. FESEM, DSC and LCR meter were used to characterize morphology and thermal properties. It was found that MWCNT were dispersed in soft segment of PU-ether. Good MWCNT dispersion was able to achieve at high temperature with short mixing time or low temperature with long mixing time. On the other hand, PU-ester/MWCNT nanocomposites, MWCNT preferred to disperse in hard segment and could be dispersed well in PU-ester at low mixing temperature.

The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Polymer Composites ◽  
Epoxy Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.

Dielectric and Thermomechanical Properties of Polypropylene/Multi-Walled Carbon Nanotubes Nanocomposites

2007 ◽  
Vol 1056 ◽  
Author(s):  
A. Kanapitsas ◽  
E. Logakis ◽  
C. Pandis ◽  
I. Zuburtikudis ◽  
P. Pissis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Dielectric Relaxation Spectroscopy ◽  
Melt Mixing ◽  
Polypropylene Nanocomposites ◽  
Multi Walled Carbon Nanotubes ◽  
Permittivity Measurements ◽  
Walled Carbon Nanotubes

ABSTRACTThe purpose of this work is to examine the dielectric, electrical and thermo-mechanical properties of multi-walled carbon nanotubes (MWCNT) filled polypropylene nanocomposites formed by melt-mixing. To that aim dielectric relaxation spectroscopy (DRS) and dymamic mechanical analysis (DTMA) were employed. The results are discussed in terms of nucleating action of MWCNT and interfacial polymer-filler interactions. Special attention is paid to percolation aspects by both ac conductivity measurements for the samples which are above the percolation threshold and permittivity measurements for the samples which are below percolation threshold.

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 Self-regulating electric heater based on elastomer, modified with multilayer carbon nanotubes

2018 ◽  
Vol 80 (3) ◽  
pp. 341-345 ◽  
Author(s):  
V. S. Yagubov ◽  
A. V. Shchegolkov
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Field ◽  
Supply Voltage ◽  
Electric Heating ◽  
Heating Element ◽  
Electric Heater ◽  
Heater Surface ◽  
Electrically Conductive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The review of modern approaches to the development of electric heating materials makes it possible to conclude that the studies of electrically conductive composites are based on using elastomers modified with nanoscale carbon materials. In the manufacturing of electric heaters, temperature self-regulation is the main property that increases their characteristics. However, researchers engaged in studying such heaters, face difficulties associated with the magnitude of supply voltage and power. In this regard, the tasks of the present work were as follows: to study the modifier characteristics for nanomodified heaters, and to select a modifier that is best dispersed in the elastomer, which will ensure the maximum magnitude of the supply voltage and the high value of the specific power of the heater. To develop an electric heater, silicone rubber modified with carbon nanotubes was used as an elastomer. The method for manufacturing the heating element nanomodified material was described. Multi-walled carbon nanotubes synthesized through the CVD method were employed as an electrically conductive modifier. Before modifying the elastomer, the carbon nanotubes were processed in a mill at a rotational speed of working blades of 25,000 rpm. Then, the nanotubes were thermally treated in a furnace until the temperature of 110 °C was reached. After that, the nanotubes and the elastomer were mixed using a BRABENDER mixer, followed by pressing and obtaining plates of the electric heating material. To ensure contact between the heater and the power source, aluminum foil, inserted into the punches before pressing, was used. The electrical conductivity of the elastic heater nanomodified material was studied using a setup (facility) constructed especially for that purpose. Based on the results obtained, a conclusion can be made on the expediency of using different multi-walled carbon nanotubes as elastomer modifiers, which form electrically conductive networks inside the elastomer and are capable of releasing heat when connected to an electrical voltage source. Employing a non-contact method of measuring the temperature field on the electric heater surface, thermograms were recorded. It was found that the temperature field is uniformly distributed on the heater surface and is stabilized at a certain time after achieving a thermal balance with the environment. From the data obtained, it can be concluded that the heating element connected to an alternating current network with a voltage of 220 V is efficient.

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