Nanocomposite Foams of Polypropylene and Carbon Nanotubes: Preparation, Characterization, and Evaluation of their Performance as EMI Absorbers

Tran, Minh-Phuong; Thomassin, Jean‐Michel; Alexandre, Michaël; Jérôme, Christine; Huynen, Isabelle; Detrembleur, Christophe

doi:10.1002/macp.201500031

Cited by 43 publications

(30 citation statements)

References 68 publications

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“…Consequently, beyond this point, the percolation threshold was observed to increase proportionally with the porosity level. Similar experimental observations and interpretations have been reported by Tran and coworkers [27,28] and Zhi et al [29] for porous nanocomposites incorporating multiwalled CNTs. Some processing techniques using high aspect ratio fillers, including CNTs [25] and GNPs [30], can result in a morphology characterized by highly oriented fillers.…”

Section: Electrical Percolation In Hybrid Systemssupporting

confidence: 89%

Conductive polymer foams with carbon nanofillers – Modeling percolation behavior

Maxian¹,

Pedrazzoli²,

Manas‐Zloczower³

2017

Express Polym. Lett.

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Abstract.A new numerical model considering nanofiller random distribution in a porous polymeric matrix was developed to predict electrical percolation behavior in systems incorporating 1D-carbon nanotubes (CNTs) and/or 2D-graphene nanoplatelets (GNPs). The numerical model applies to porous systems with closed-cell morphology. The percolation threshold was found to decrease with increasing porosity due to filler repositioning as a result of foaming. CNTs were more efficient in forming a percolative network than GNPs. High-aspect ratio (AR) and randomly oriented fillers were more prone to form a network. Reduced percolation values were determined for misaligned fillers as they connect better in a network compared to aligned ones. Hybrid CNT-GNP fillers show synergistic effects in forming electrically conductive networks by comparison with single fillers.

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Section: Electrical Percolation In Hybrid Systemssupporting

confidence: 89%

Conductive polymer foams with carbon nanofillers – Modeling percolation behavior

Maxian¹,

Pedrazzoli²,

Manas‐Zloczower³

2017

Express Polym. Lett.

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“…This kind of lightweight and multifunctional material is mainly composed of a polymer matrix, conductive fillers, and micropores. Therein, thermoplastic FCPCs, which are obtained with low‐boiling hydrocarbons or thermolabile chemical compounds, are the most reported types; these include poly(methyl methacrylate)–graphene foams, polyethylene–multiwalled carbon nanotube (MWCNT) foams, polystyrene–MWCNT foams, polypropylene–carbon fiber foams, polypropylene–MWCNT foams, and poly(styrene‐ b ‐butadiene‐ co ‐styrene‐ b ‐styrene)–carbon black (CB) foams . However, these foams all have uniform disadvantages; they lack sufficient strength and thermostability, and this largely restricts their applications.…”

Section: Introductionmentioning

confidence: 99%

Epoxy–carbon black composite foams with tunable electrical conductivity and mechanical properties: Foaming improves the conductivity

Jia

Bao

2017

J of Applied Polymer Sci

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In this study, conductive epoxy foams with different carbon black (CB) contents were fabricated with expandable microspheres as foaming agents. The effect of the CB content, microsphere concentration, precuring time, and foaming temperature on the electrical conductivity and compressive properties of the obtained foams were investigated systematically. The differential scanning calorimeter and rheological tests confirmed that the CB accelerated the curing reaction, increased the onset viscosity of the epoxy blend during foaming, and affected the foaming process. In addition, all of the parameters, including the CB content, microsphere concentration, precuring time, and foaming temperature, were confirmed to change the foam structures and further change the conductivity and mechanical properties. The electrical properties test revealed that the foaming process improved the conductivity of the composites. On the basis of the electrical properties test results and scanning electron microscope images, a flow-induced CB aggregation mechanism is presented, in which the thermally triggered microsphere expansion pushed the resins away, squeezed the CB together, and changed the CB distribution throughout the foams. This made more conductivity paths. The obtained foam could just be used as an antistatic material, but it gave us an example for exploring lightweight and low-cost conductive epoxy foams with other applications, for example, electromagnetic shielding.

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“…For electromagnetic shielding with good damping properties, foams made of PP with MWCNT can be used. Today, sCO 2 is the main blowing agent utilized 34,35 which allows the continuous production of PP foams by extrusion and injection molding. For injection molding 19 and batch production, chemical agents like AZO can also be employed; with this last agent, however, the foaming is less controllable, mainly because the AZO is dispersed as solid particles and thus, highly dispersive mixing methods should be used.…”

Section: Introductionmentioning

confidence: 99%

Effect of MWCNT carboxyl functionalization on the shear rheological and electrical properties of HMS-PP/MWCNT foams

Bianchin

Melo

Bretas

2020

Journal of Cellular Plastics

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Different concentrations of multiwall carbon nanotubes (MWCNT) and carboxyl functionalized MWCNT (MWCNT-COOH) were added to a high melt strength polypropylene (HMS-PP) to produce foams with high dielectric constants, using azodicarbonamide (AZO) as blowing agent. The AZO foaming behavior and the crystallization, thermal properties, steady state and oscillatory shear rheological properties of the nanocomposites were analyzed by polarized light optical microscopy (PLOM), differential scanning calorimetry (DSC), thermogravimetry analyses (TGA) and parallel plate rheometry. The morphology, the dielectric and dynamic mechanical properties (DMTA) of the foams were also studied by scanning electron microscopy (SEM), impedance spectroscopy and bending method, respectively. A decrease in crystallite size and an increase in the HMS-PP overall crystallinity promoted by the presence of both types of MWCNTs was observed, as well as an increase in the crystallization temperatures. From these results and from the analyses of the rheological properties, it was possible to predict that the 5 wt.% MWCNT foam would have the lowest bubble growth rate, the 1.5 wt.% MWCNT-COOH the highest, while the 3 wt.% MWCNT-COOH composition would have the slowest bubble stability (and consequently the highest cellular density) and the 1.5 wt.% MWCNT-COOH the fastest. Also, it was possible to predict that only the 5 wt.% MWCNT-COOH foam would have a percolated and electrically conductive structure. All these predictions were confirmed by the resultant morphology and impedance spectroscopy results. The highest mechanical damping was displayed by the 3 wt.% MWCNT-COOH foam, while the lowest by the 5 wt.% MWCNT-COOH foam. Regarding the dielectric properties, the 1.5 wt% MWCNT-COOH foam was found to be the most suitable to be used as a capacitor material; this foam was also the less dense of all the samples.

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Nanocomposite Foams of Polypropylene and Carbon Nanotubes: Preparation, Characterization, and Evaluation of their Performance as EMI Absorbers

Cited by 43 publications

References 68 publications

Conductive polymer foams with carbon nanofillers – Modeling percolation behavior

Conductive polymer foams with carbon nanofillers – Modeling percolation behavior

Epoxy–carbon black composite foams with tunable electrical conductivity and mechanical properties: Foaming improves the conductivity

Effect of MWCNT carboxyl functionalization on the shear rheological and electrical properties of HMS-PP/MWCNT foams

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