Hierarchical Composite Materials

Abstract

Conventional continuous fiber reinforced polymer composites (FRP) have extensively been used as structural elements in a myriad of sectors, such as civil, transport, energy and marine, among other, due to their superior mechanical properties, low weight and ease of processing. However, the relatively weak compression and interlaminar properties of these composites limit their application field. Interest is, therefore, growing in the development of hierarchical or multiscale composites, in which, a nanoscale filler reinforcement is utilized to alleviate the existing limitations associated with the matrix dominated properties. The majority of the work has focused on carbon nanotubes, CNTs due to their extraordinary intrinsic properties. In addition to their outstanding mechanical properties, CNTs possess excellent electrical and mechanical properties, making them attractive materials as reinforcement for polymer matrices. CNTs provide both intralaminar and interlaminar reinforcement, thus improving delamination resistance and through thickness properties, without compromising in-plane performance. In recent years, there has been an increasing interest in the use of graphene as reinforcement of polymer nanocomposites. Compared to CNTs, graphene has advantages such as lower cost, higher surface area and a greater ease of processing. Graphene is more easily dispersed in the resin and causes a lower viscosity increase, which can facilitate the impregnation of the fibers. In this work, the fabrication and characterization of hierarchical composites are analyzed through the inclusion of graphene to conventional continuous carbon fiber reinforced epoxy composites by vacuum-assisted resin transfer molding.

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