Multifunctional nanocomposite foams based on polypropylene with carbon nanofillers

Abstract

This work considers the preparation and characterization of polypropylene foams with\ud variable concentrations of graphene and carbon nanofibres, focussing on the influence\ud of the foaming process and the nanofillers on the microstructural and dynamic-mechanical-\ud thermal properties of the foams. Great differences were found in terms of foam\ud morphology depending on the type of foaming process, with foams prepared by physical\ud foaming showing a vertically deformed cell structure, while chemical foams presented\ud an isotropic-like cellular structure. The addition of graphene resulted in foams with\ud higher cell densities and more uniform cellular structures when compared to the ones\ud with nanofibres. All these considerations are of extreme importance, as some of\ud the most promising applications of these polymer foams require a good electromagnetic\ud interference shielding efficiency, which greatly depends on the developed foam\ud morphology.Peer ReviewedPostprint (published version

Graphene nanoplatelets-reinforced polyetherimide foams prepared by water vapor-induced phase separation

“…On the other hand, the strong sharp diffraction signal at 2% = 26.5°, corresponding to the reflection of graphene nanoplatelets' (002) crystal diffraction plane [24] (see insert in Figure 7), although is reduced with decreasing the concentration of nanoplatelets, does not fully disappear after foaming, indicating that there is no full exfoliation of the graphene nanoplatelets [1,14,15].…”

“…The growing necessity of weight reduction in the majority of industries continuously pushes the boundaries of material selection and production techniques to obtain lighter structures with improved specific properties and added functionalities [1][2][3][4]. For this reason, weight reduction of polymer-based composites by means of foaming, merged with integration of multifunctional fillers, has recently aroused a great interest [3,4].…”

“…Carbon-based nanofillers, and particularly graphene, have recently attracted much attention owing to their inherently high mechanical and transport properties, which have provided wide sets of possibilities in sectors such as electronics or aerospace. Due to their conducting structure-dependent electronic properties, the role of these carbon nanoparticles has been suggested as a possible option to modify the electronic properties of polymers, partially solving some of the problems regarding the use of conductive polymers [1]. Among carbon-based nanofillers, graphene and graphene-derived materials have caught a great deal of attention due to their extraordinary combination of properties, such as high surface area, aspect ratio, tensile strength, thermal and electrical conductivities, electromagnetic interference (EMI) shielding efficiency, flexibility, transparency or low coefficient of thermal expansion [5][6][7][8].…”

Mechanical behaviour of cyclic olefin copolymer/exfoliated graphite nanoplatelets nanocomposites foamed through supercritical carbon dioxide

“…saturation and foaming temperature) was investigated [40]. Antunes et al [41] devoted their attention on the microstructural features and the ther-mo-mechanical behaviour of polypropylene foams containing xGnP and expanded through scCO 2 . A similar topic was presented in the paper of Yeh et al [42] about the effect of dispersion method and process variables on the properties of supercritical CO 2 foamed polystyrene/graphite nanocomposite foams.…”

Influence of polyamide–imide concentration on the cellular structure and thermo-mechanical properties of polyetherimide/polyamide–imide blend foams

“…In this sense, lightweight materials with improved specific mechanical properties and functionalities are attracting considerable attention, with polymer foams appearing as promising candidates with possibility of customization for specific purposes by controlling their composition [1][2][3][4].…”