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Graphene nanoplatelets (GNPs), the most important mass-produced graphene, are fabricated as a mechanical reinforcement for epoxy matrix nanocomposites. Current performance of GNPs as a reinforcing filler is limited by their agglomeration and weak interfacial interaction with certain polymer matrices. Herein, an approach to produce noncovalently functionalized GNPs (F-GNPs) is reported that can be extended to the industrial level of mass production. The one-step functionalization process uses melamine, a low-cost chemical, to improve the interfacial adhesion and dispersion in an epoxy matrix. The mechanical properties of nanocomposites prepared with the F-GNP flakes are much better (94.3% and 35.3% enhancements in Young's modulus and tensile strength, respectively) than those of the unfilled pure epoxy. Experimental data are analyzed using the Halpin-Tsai model. The fabrication process developed in this paper provides a strategy to use GNPs at the industrial level in lightweight and high-strength structural applications. [ABSTRACT FROM AUTHOR]

Thermoplastic resin used as a matrix of fiber reinforced thermoplastics (FRTPs) is composed of high polymers that remain highly viscous even at a higher temperature than their melting points. As a result, they need a higher temperature, a higher pressure and longer process time to allow them to bond with fibers and consequently require large and specialized facilities. In this paper, a simple and fast fabrication method of vacuum assisted resin transfer molding (VARTM) method for hybrid fiber reinforced thermoplastic (HFRTP) was introduced. In order to fabricate HFRTP with the VARTM, glass and carbon fabrics were used as reinforcement and in-situ polymerizable epsilon caprolactam (ɛ-caprolactam) was used as the matrix. The obtained HFRTP had neither voids nor unfilled parts because the liquid state of ɛ-caprolactam was very low viscosity before polymerization. The fabrication method of the HFRTP proposed here showed a faster fabrication one compared with conventional fabrication methods. In order to apply this HFRTP to automotive structures, the performances of the HFRTP showed not only superior mechanical properties but also suitable for high-speed molding without expensive facilities, namely, within a few minute process time with a vacuum pump because they could be released from the mold without a cooling process. [ABSTRACT FROM AUTHOR]