Morphology and electrical properties of injection-molded PP carbon-based nanocomposites

Zaccone, Marta; Armentano, Ilaria; Torre, Luigi; Cesano, Federico; Cravanzola, Sara; Scarano, Domenica; Frache, Alberto; Monti, Marco

doi:10.1063/1.5016771

Cited by 3 publications

(3 citation statements)

References 16 publications

(16 reference statements)

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“…In particular, carbon nanotubes (CNTs) have been identified as a very promising filler to obtain high-performance nanocomposites [ 3 , 4 ]. Due to their chain-like aggregated structure, they tend to easily form a conductive path within the polymer matrix, which is more effective if compared with other conductive additives, and which is well-described by the percolation theory [ 5 , 6 , 7 ]. For this reason, they can be exploited for a variety of industrial applications, such as, sensors and electromagnetic interference (EMI) shielding devices [ 8 , 9 , 10 , 11 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of Injection Molding Conditions on Crystalline Structure and Electrical Resistivity of PP/MWCNT Nanocomposites

et al. 2020

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Polypropylene (PP) / multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by melt-mixing and used to manufacture samples by injection molding. The effect of processing conditions on the crystallinity and electrical resistivity was studied. Accordingly, samples were produced varying the mold temperature and injection rate, and the DC electrical resistivity was measured. The morphology of MWCNT clusters was studied by optical and electron microscopy, while X-ray diffraction was used to study the role of the crystalline structure of PP. As a result, an anisotropic electrical behavior induced by the process was observed, which is further influenced by the injection molding processing condition. It was demonstrated that a reduction of electrical resistivity can be obtained by increasing mold temperature and injection rate, which was associated to the formation of the γ-phase and the related inter-cluster morphology of the MWCNT conductive network.

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Section: Introductionmentioning

confidence: 99%

Effect of Injection Molding Conditions on Crystalline Structure and Electrical Resistivity of PP/MWCNT Nanocomposites

et al. 2020

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“…This is due to the shear stress induced on the molten material, by the flow during the mold-filling phase, which changes over the thickness and the surface of the mold cavity and the produced component [ 12 ]. In the case of polymers filled with conductive particles, this inhomogeneity in the morphology, results in an equivalent inhomogeneity in the electrical behavior [ 3 , 14 , 30 , 41 ]. As an example, Cesano et al [ 30 ] highlighted this effect in the thickness of PP-MWCNT nanocomposites, while Pötschke et al [ 44 ] studied this phenomenon on several positions over the surface of polycarbonate-MWCNT nanocomposites.…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, thanks to their tubular shape with a very high aspect ratio, they can turn the insulating behavior of polymers into conductive, even at very low content [ 2 ]. This is particularly interesting because a low CNT fraction does not modify the mechanical performance of the pristine polymer in which they are embedded, differently from other carbon-based additives (e.g., carbon black or graphite), which usually lead to brittle materials, due to the considerable amount needed to significantly modify the electrical behavior [ 3 , 4 , 5 , 6 , 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Dielectric Spectroscopy of PP/MWCNT Nanocomposites: Relationship with Crystalline Structure and Injection Molding Condition

Monti

Zaccone

Frache³

et al. 2021

Nanomaterials

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In this paper, we study the correlation between the dielectric behavior of polypropylene/multi-walled carbon nanotube (PP/MWCNT) nanocomposites and the morphology with regard to the crystalline structure, nanofiller dispersion and injection molding conditions. As a result, in the range of the percolation threshold the dielectric behavior shifts to a more frequency-independent behavior, as the mold temperature increases. Moreover, the position further from the gate appears as the most conductive. This effect has been associated to a modification of the morphology of the MWCNT clusters induced by both the flow of the molten polymer during the processing phase and the variation of the crystalline structure, which is increasingly constituted by γ-phase as the mold temperature increases. The obtained results allow one to understand the effect of tuning the processing condition in the frequency-dependent electrical behavior of PP/MWCNT injection-molded nanocomposites, which can be successfully exploited for an advanced process/product design.

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Effect of Filler Morphology on the Electrical and Thermal Conductivity of PP/Carbon-Based Nanocomposites

Zaccone

Frache²,

Torre

et al. 2021

J. Compos. Sci.

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In this paper, we studied the effect of different carbon-based nanostructures on the electrical and mechanical properties of polypropylene (PP) nanocomposites. Multi-walled carbon nanotubes (MWCNT), expanded graphite (EG), and two different carbon black nanoparticles (CB) have been dispersed at several weight contents in the polymer matrix through a melt extrusion process. The produced nanocomposites have been used to obtain samples for the characterization by injection molding. The dispersion of the nanoparticles in the matrix has been evaluated by scanning electron microscopy (SEM) analysis. The electrical characterization has been performed both in DC and in AC configuration. The mechanical properties have been evaluated with both tensile test and impact strength (Izod). The thermal conductivity has been also evaluated. As a result, MWCNTs are the nanoadditive with the lowest electrical percolation threshold. This allows MWCNT nanocomposite to drastically change the electrical behavior without a significant embrittlement observed with the other nanoadditives. However, CB with the lowest surface area allows the highest conductivity, even though at a high particle content. EG has a limited effect on electrical properties, but it is the only one with a significant effect on thermal conductivity.

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Morphology and electrical properties of injection-molded PP carbon-based nanocomposites

Cited by 3 publications

References 16 publications

Effect of Injection Molding Conditions on Crystalline Structure and Electrical Resistivity of PP/MWCNT Nanocomposites

Effect of Injection Molding Conditions on Crystalline Structure and Electrical Resistivity of PP/MWCNT Nanocomposites

Dielectric Spectroscopy of PP/MWCNT Nanocomposites: Relationship with Crystalline Structure and Injection Molding Condition

Effect of Filler Morphology on the Electrical and Thermal Conductivity of PP/Carbon-Based Nanocomposites

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