scholarly journals Characterizations of Polypropylene/Single-Walled Carbon Nanotube Nanocomposites Prepared by the Novel Melt Processing Technique with a Controlled Residence Time

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1395
Author(s):  
Dongho Kang ◽  
Sungwook Hwang ◽  
Bichnam Jung ◽  
Jinkie Shim
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Residence Time ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Processing Technique ◽  
Melt Processing ◽  
Melt Mixing ◽  
Single Walled Carbon ◽  
Twin Screw

Melt processing is considered one of the favored techniques to produce polymer nanocomposites with various inorganic fillers such as graphene and carbon nanotubes (CNTs). Due to their superior conductivity and tensile properties, among others, CNTs have been applied in broad applications. When a low filler fraction is desired, a high degree of dispersion is required in order to benefit from the intrinsic properties of CNTs. However, due to their high cohesive energy, dispersing CNTs in polymer melts is a difficult task. This study employed the melt mixing technique with a controlled residence time of 20 min to disperse single-walled carbon nanotubes (SWNTs) into a polypropylene matrix. The composites were prepared by using a corotating twin-screw extruder equipped with a back-conveying element with varying amounts of SWNTs from 0.29 to 6.56 wt.%. Mechanical, electrical, morphological, and rheological properties were evaluated. Due to the filler effect, storage, loss modulus, and complex viscosity increased with the SWNT content. Based on the van Gurp–Palmen plot, 0.29 wt.% SWNTs was the rheological percolation threshold, and the electrical property measurement revealed a 1.4 wt.% SWNT electrical percolation threshold based on the statistical percolation theory. Relatively large agglomerates were found when the SWNT content increased more than 1.28 wt.%.

scholarly journals Dynamic Mechanical, Dielectrical, and Rheological Analysis of Polyethylene Terephthalate/Carbon Nanotube Nanocomposites Prepared by Melt Processing

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Juris Bitenieks ◽  
Remo Merijs Meri ◽  
Janis Zicans ◽  
Krisjanis Buks
Keyword(s):  
Carbon Nanotube ◽  
Polyethylene Terephthalate ◽  
Complex Viscosity ◽  
Melt Processing ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Dynamic Mechanical ◽  
Morphological Studies ◽  
Twin Screw ◽  
And Storage

The polyethylene terephthalate/carbon nanotube (PET/CNT) nanocomposites were prepared by melt mixing using a twin screw extruder. CNT content was varied up to 5 wt. %. Morphology as well as dynamic mechanical, calorimetric, and rheological properties of the PET/CNT nanocomposites was investigated. Morphological studies indicated that CNT bundles are regularly distributed within the polymer matrix creating a connected network structure which significantly affects the nanocomposite properties. Dynamic mechanical thermal analysis revealed increase in storage and loss modules of the investigated PET nanocomposites by increasing the content of CNTs. Differential scanning calorimetry results demonstrated increase in crystallinity of the investigated PET nanocomposites upon addition of the nanofiller. Rheological studies demonstrated that CNT addition up to 5 wt. % caused increment in complex viscosity and storage modulus. Rheological percolation threshold was observed to be 0.83 wt. % of CNT concentration, respectively.

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.

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.

Anhydride/Epoxy Functionalized Blends: Mechanical, Rheological and Thermal Properties

2001 ◽  
Vol 702 ◽  
Author(s):  
Goknur Bayram ◽  
Ulku Yilmazer
Keyword(s):  
Thermal Properties ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Chain Extension ◽  
Screw Extruder ◽  
Batch Mixing ◽  
Twin Screw ◽  
Styrene Maleic Anhydride ◽  
Batch Mixer ◽  
Fine Morphology

ABSTRACTBlends of styrene-maleic anhydride (SMAH) and polyethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) were produced in a batch mixer and in a corotating twin screw extruder. E-MA-GMA concentration was varied from 0 % to 50 %. Batch mixing indicated that the blend system was reactive. Extruded blends were characterized in terms of rheological, thermal and mechanical properties, and their morphology was observed. Rheological properties such as the storage modulus, loss modulus and complex viscosity exhibited maxima at 25 % EMA-GMA content. The blends had fine morphology as observed by scanning electron microscopy. Thermal properties were not significantly affected by the change in epoxy concentration. As E-MA-GMA concentration increased, tensile strength and modulus of elasticity decreased, but percent strain at break increased. These observations could be explained in terms of the chain extension / branching reactions that occurred in mixing the blends.

scholarly journals Segregated network polymer/carbon nanotubes composites

2004 ◽  
Vol 2 (2) ◽  
pp. 363-370 ◽  
Author(s):  
A. Mierczynska ◽  
J. Friedrich ◽  
H. Maneck ◽  
G. Boiteux ◽  
J. Jeszka
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Network Formation ◽  
Processing Parameters ◽  
Low Grade ◽  
Single Walled Carbon ◽  
Conductive Composites ◽  
Grade Material

AbstractIn this work we present the preparation of conductive polyethylene/carbon nanotube composites based on the segregated network concept. Attention has been focused on the effect of decreasing the amount of filler necessary to achieve low resistivity. Using high- and low-grade single-walled carbon nanotube materials we obtained conductive composites with a low percolation threshold of 0.5 wt.% for high-grade nanotubes, about 1 wt% for commercial nanotubes and 1.5 wt% for low-grade material. The higher percolation threshold for low-grade material is related to low effectiveness of other carbon fractions in the network formation. The electrical conductivity was measured as a function of the single-walled carbon nanotubes content in the polymer matrix and as a function of temperature. It was also found that processing parameters significantly influenced the electrical conductivity of the composites. Raman spectroscopy was applied to study single wall nanotubes in the conductive composites.

scholarly journals Effect of Processing Temperature and the Content of Carbon Nanotubes on the Properties of Nanocomposites Based on Polyphenylene Sulfide

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3816
Author(s):  
Kamil Dydek ◽  
Paulina Latko-Durałek ◽  
Agata Sulowska ◽  
Michał Kubiś ◽  
Szymon Demski ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Loss Modulus ◽  
Complex Viscosity ◽  
Polyphenylene Sulfide ◽  
Degree Of Crystallinity ◽  
Processing Temperature ◽  
Scanning Calorimetry ◽  
Mwcnt Content ◽  
Multi Wall Carbon Nanotubes ◽  
Thermal And Electrical Properties

The study aimed to investigate the effect of processing temperature and the content of multi-wall carbon nanotubes (MWCNTs) on the rheological, thermal, and electrical properties of polyphenylene sulfide (PPS)/MWCNT nanocomposites. It was observed that the increase in MWCNT content influenced the increase of the complex viscosity, storage modulus, and loss modulus. The microscopic observations showed that with an increase in the amount of MWCNTs, the areal ratio of their agglomerates decreases. Thermogravimetric analysis showed no effect of processing temperature and MWCNT content on thermal stability; however, an increase in stability was observed as compared to neat PPS. The differential scanning calorimetry was used to assess the influence of MWCNT addition on the crystallization phenomenon of PPS. The calorimetry showed that with increasing MWCNT content, the degree of crystallinity and crystallization temperature rises. Thermal diffusivity tests proved that with an increase in the processing temperature and the content of MWCNTs, the diffusivity also increases and declines at higher testing temperatures. The resistivity measurements showed that the conductivity of the PPS/MWCNT nanocomposite increases with the increase in MWCNT content. The processing temperature did not affect resistivity.

Specific Interactions Induced Dispersion and Confinement of Multi-Walled Carbon Nanotubes in Co-continuous Polymer Blends

2008 ◽  
Vol 8 (4) ◽  
pp. 1867-1879 ◽  
Author(s):  
Suryasarathi Bose ◽  
Arup R. Bhattacharyya ◽  
Pravin V. Kodgire ◽  
Ajit R. Kulkarni ◽  
Ashok Misra
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Multiwall Carbon Nanotubes ◽  
Acrylonitrile Butadiene Styrene ◽  
Polyamide 6 ◽  
Strong Impact ◽  
Specific Interactions ◽  
Melt Mixing ◽  
Uniform Dispersion ◽  
High Dielectric

Multiwall carbon nanotubes (MWNT) were melt-mixed with 50/50 co-continuous blends of polyamide 6 (PA6) and acrylonitrile-butadiene-styrene (ABS). Blending sequence and moulding processes were found to have a strong impact on the conductivity of the blends with MWNT. Aggregated nature of the tubes, migration during processing and skin-core morphology generated during mould cooling step were found to be crucial parameters affecting the electrical conductivity of the blends. We report here the role of a reactive modifier: sodium salt of 6-amino hexanoic acid (Na-AHA) aiding in uniform dispersion of the MWNT in the 50/50 PA6/ABS blends and restricting the tubes utilizing specific interactions during melt-mixing in the PA6 phase in the blends. We further varied the MWNT to Na-AHA ratio from 1:1 to 1:15 to optimize the concentration of MWNT required in achieving lower electrical percolation threshold in co-continuous PA6/ABS blends. The associated percolation threshold was observed at ∼0.5 wt% MWNT with high dielectric constant.

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