scholarly journals Thermal/Electrical Properties and Texture of Carbon Black PC Polymer Composites near the Electrical Percolation Threshold

2021 ◽  
Vol 5 (8) ◽  
pp. 212
Author(s):  
Valentina Brunella ◽  
Beatrice Gaia Rossatto ◽  
Chiara Mastropasqua ◽  
Federico Cesano ◽  
Domenica Scarano
Keyword(s):  
Electrical Properties ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Textural Properties ◽  
Thermoplastic Polymer ◽  
Conductivity Measurements ◽  
Scanning Calorimetry ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold ◽  
Dc Electrical Properties

Polycarbonate (PC), a thermoplastic polymer with excellent properties, is used in many advanced technological applications. When PC is blended with other polymers or additives, new properties, such as electrical properties, can be available. In this study, carbon black (CB) was melt-compounded with PC to produce polymer compounds with compositions (10–16 wt.% of CB), which are close to or above the electrical percolation threshold (13.5–14 wt.% of CB). Effects due to nanofiller dispersion/aggregation in the polymer matrix, together with phase composition, glass transition temperature, morphology and textural properties, were studied by using thermal analysis methods (thermogravimetry and differential scanning calorimetry) and scanning electron microscopy. The DC electrical properties of these materials were also investigated by means of electrical conductivity measurements and correlated with the “structure” of the CB, to better explain the behaviour of the composites close to the percolation threshold.

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 A Numerical Study on Electrical Percolation of Polymer-Matrix Composites with Hybrid Fillers of Carbon Nanotubes and Carbon Black

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yuli Chen ◽  
Shengtao Wang ◽  
Fei Pan ◽  
Jianyu Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Polymer Matrix ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Electrical Percolation ◽  
Hybrid Fillers ◽  
Nonlinear Relation ◽  
Electrical Percolation Threshold

The electrical percolation of polymer-matrix composites (PMCs) containing hybrid fillers of carbon nanotubes (CNTs) and carbon black (CB) is estimated by studying the connection possibility of the fillers using Monte Carlo simulation. The 3D simulation model of CB-CNT hybrid filler is established, in which CNTs are modeled by slender capped cylinders and CB groups are modeled by hypothetical spheres with interspaces because CB particles are always agglomerated. The observation on the effects of CB and CNT volume fractions and dimensions on the electrical percolation threshold of hybrid filled composites is then carried out. It is found that the composite electrical percolation threshold can be reduced by increasing CNT aspect ratio, as well as increasing the diameter ratio of CB groups to CNTs. And adding CB into CNT composites can decrease the CNT volume needed to convert the composite conductivity, especially when the CNT volume fraction is close to the threshold of PMCs with only CNT filler. Different from previous linear assumption, the nonlinear relation between CB and CNT volume fractions at composite percolation threshold is revealed, which is consistent with the synergistic effect observed in experiments. Based on the nonlinear relation, the estimating equation for the electrical percolation threshold of the PMCs containing CB-CNT hybrid fillers is established.

scholarly journals Incorporation of Carbon Nanofillers Tunes Mechanical and Electrical Percolation in PHBV:PLA Blends

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1371 ◽  
Author(s):  
Jesse Arroyo ◽  
Cecily Ryan
Keyword(s):  
Phase Separation ◽  
Electrical Properties ◽  
Percolation Threshold ◽  
Mechanical Analysis ◽  
Poly Lactic Acid ◽  
Peak Reduction ◽  
Scanning Calorimetry ◽  
Electrical Percolation ◽  
Mechanical And Electrical Properties ◽  
Electrical Conductivities

Biobased fillers, such as bio-derived cellulose, lignin byproducts, and biochar, can be used to modify the thermal, mechanical, and electrical properties of polymer composites. Biochar (BioC), in particular, is of interest for enhancing thermal and electrical conductivities in composites, and can potentially serve as a bio-derived graphitic carbon alternative for certain composite applications. In this work, we investigate a blended biopolymer system: poly(lactic acid) (PLA)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), and addition of carbon black (CB), a commonly used functional filler as a comparison for Kraft lignin-derived BioC. We present calculations and experimental results for phase-separation and nanofiller phase affinity in this system, indicating that the CB localizes in the PHBV phase of the immiscible PHBV:PLA blends. The addition of BioC led to a deleterious reaction with the biopolymers, as indicated by blend morphology, differential scanning calorimetry showing significant melting peak reduction for the PLA phase, and a reduction in melt viscosity. For the CB nanofilled composites, electrical conductivity and dynamic mechanical analysis supported the ability to use phase separation in these blends to tune the percolation of mechanical and electrical properties, with a minimum percolation threshold found for the 80:20 blends of 1.6 wt.% CB. At 2% BioC (approximately the percolation threshold for CB), the 80:20 BioC nanocomposites had a resistance of 3.43 × 10 8 Ω as compared to 2.99 × 10 8 Ω for the CB, indicating that BioC could potentially perform comparably to CB as a conductive nanofiller if the processing challenges can be overcome for higher BioC loadings.

A promising approach to low electrical percolation threshold in PMMA nanocomposites by using MWCNT-PEO predispersions

2016 ◽  
Vol 111 ◽  
pp. 253-262 ◽  
Author(s):  
Seyed Mohammad Mir ◽  
Seyed Hassan Jafari ◽  
Hossein Ali Khonakdar ◽  
Beate Krause ◽  
Petra Pötschke ◽  
...  
Keyword(s):  
Percolation Threshold ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold

scholarly journals Broadband Dielectric Properties of Fe2O3·H2O Nanorods/Epoxy Resin Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Darya Meisak ◽  
Jan Macutkevic ◽  
Dzmitry Bychanok ◽  
Algirdas Selskis ◽  
Juras Banys ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Percolation Threshold ◽  
Epoxy Resin ◽  
Polymer Matrix ◽  
Finite Conductivity ◽  
Resin Composites ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold ◽  
Percolation Network ◽  
Properties Of Composites

A series of polymer composites based on epoxy resin with a 5–40 vol.% concentration of goethite (Fe2O3·H2O) nanorods was produced. The electrical percolation threshold in these composites was determined as 30 vol.% of nanorods. The dielectric properties of the composites both below and above the percolation threshold were studied in a wide temperature (200 K–450 K) and frequency (from Hz to THz) ranges. The dielectric properties of composites below the percolation threshold are mainly determined by the relaxation in a pure polymer matrix. The electrical properties of composites above the percolation threshold are determined by the percolation network, which is formed by the goethite nanorods inside the polymer matrix. Due to the finite conductivity of the epoxy resin, the electrical conductivity at high temperatures occurs in the composites both above and below the percolation threshold.

Qualitative Equivalence Between Electrical Percolation Threshold and Effective Thermal Conductivity in Polymer/Carbon Nanocomposites

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Majid Baniassadi ◽  
Akbar Ghazavizadeh ◽  
Yves Rémond ◽  
Said Ahzi ◽  
David Ruch ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Percolation Threshold ◽  
Effective Thermal Conductivity ◽  
Electrical Percolation ◽  
Aspect Ratios ◽  
Wide Range ◽  
Statistical Continuum ◽  
Electrical Percolation Threshold

In this study, a qualitative equivalence between the electrical percolation threshold and the effective thermal conductivity of composites filled with cylindrical nanofillers has been recognized. The two properties are qualitatively compared on a wide range of aspect ratios, from thin nanoplatelets to long nanotubes. Statistical continuum theory of strong-contrast is utilized to estimate the thermal conductivity of this type of heterogeneous medium, while the percolation threshold is simultaneously evaluated using the Monte Carlo simulations. Statistical two-point probability distribution functions are used as microstructure descriptors for implementing the statistical continuum approach. Monte Carlo simulations are carried out for calculating the two-point correlation functions of computer generated microstructures. Finally, the similarities between the effective conductivity properties and percolation threshold are discussed.

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