Enhancement of the thermal conductivity of polypropylene with low loadings of CuAg alloy nanoparticles and graphene nanoplatelets

• Published in: Materials today communications Vol. 21; p. 100695
• Main Authors: Medellín-Banda, Diana Iris, Navarro-Rodríguez, Dámaso, Fernández-Tavizón, Salvador, Ávila-Orta, Carlos Alberto, Cadenas-Pliego, Gregorio, Comparán-Padilla, Victor Eduardo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2019
• Subjects: CuAg alloy; Graphene; Nanocomposite; Polypropylene; Thermal conductivity; CuAg alloy; Thermal conductivity; Nanocomposite; Polypropylene; Graphene
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2019.100695

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•Sequential feeding of Cu and Ag salts affords silver-rich shell CuAg nanoalloys.•Nanocomposites showed improved thermal conductivity as compared with neat iPP.•Charge carrier traps allows the preparation of electric insulating nanocomposites.•The thermal stability of ternary nanocomposites was improved by synergistic effects.
Isotactic polypropylene (iPP), silver-rich shell CuAg nanoalloys and graphene nanoplatelets (GNPs) were used to prepare thermally conductive binary (iPP/CuAg and iPP/GNPs) and ternary (iPP/CuAg/GNPs) nanocomposites with filler compositions from 0.1 to 5 wt.% through melt processing. All nanocomposites were thermally and electrically characterized. Results showed that both nanoparticles nucleate the crystallization of iPP, shifting the crystallization transition toward higher temperature as compared with that of iPP. The nanoparticles dispersion was not optimum but was enough to make the nanocomposites thermally conductive between 0.65 and 1.56 W m−1 K−1 and more thermally stable (443 °C) than neat iPP (347 °C). For the iPP/CuAg nanocomposites, the increase in the electrical conductivity from 10−15 to 10−3 S m−1 suggests the formation of a percolated network. In contrast, for iPP/GNPs nanocomposites, no improvement in this property was observed. Finally, for iPP/CuAg/GNPs nanocomposites, the measured electrical conductivity (10−15 S m−1) suggests that the polymer-GNP interface is acting as a charge carrier trap. This effect is commonly reported in binary nanocomposites but little or no data exists for ternary NCs.