A very interesting field of research on advanced composite materials is the possibility to integrate new functionalities and specific\nimprovements acting on the matrix of the composite by means of a nanocharged resin. In this way, the composite becomes a\nso-called â??multiscale compositeâ? in which the different phases change from nano to macro scale. For example, the incorporation of\nnanoscale conductive fillers with intrinsically high electrical conductivity could allow a tailoring of this property for the final\nmaterial. The properties of carbon nanotubes (CNT) make them an effective candidate as fillers in polymer composite systems\nto obtain ultralight structural materials with advanced electrical and thermal characteristics. Nevertheless, several problems are\nrelated to the distribution in the matrix and to the processability of the systems filled with CNT. Existing liquid molding\nprocesses such as resin transfer molding (RTM) and vacuum-assisted resin transfer molding (VARTM) can be adapted to\nproduce carbon fiber reinforced polymer (CFRP) impregnated with CNT nanofilled resins. Unfortunately, the loading of more\nthan 0.3-0.5% of CNT can lead to high resin viscosities that are unacceptable for such kind of processes. In addition to the\nviscosity issues that are related to the high CNT content, a filtration effect of the nanofillers caused by the fibrous medium may\nalso lead to inadequate final component quality. This work describes the development of an effective manufacturing process of a\nfiber-reinforced multiscale composite panel, with a tetra-functional epoxy matrix loaded with carbon nanotubes to increase its\nelectrical properties and with GPOSS to increase its resistance to fire. A first approach has been attempted with a traditional\nliquid infusion process. As already anticipated, this technique has shown considerable difficulties related both to the low level of\nimpregnation achieved, due to the high viscosity of the resin, and to the filtration effects of the dispersed nanocharges. To\novercome these problems, an opportunely modified process based on a sort of film infusion has been proposed. This\nmodification has given an acceptable result in terms of impregnation and morphological arrangement of CNTs in nanofilled\nCFRP. Finally, the developed infiltration technique has been tested for the manufacture of a carbon fiber-reinforced panel with a\nmore complex shape.
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