Graphene/benzoxazine nanocomposites with multifunctional properties V.García-Martínez 1* , M.R. Gude 1 , A. Ureña 2 1 FIDAMC. Avenida Rita Levi Montalcini 29, Getafe, Spain 2 Department of Applied Mathematics, Materials Science and Engineering and Electronics Technology Universidad Rey Juan Carlos, Móstoles, Spain *Email: Vanessa.Garcia.External@fidamc.es Benzoxazines are thermosetting resins that have been recently introduced in the aircraft industry as an alternative to bismaleimide resins (BMI) for those applications in which high temperature or FST (fire-smoke-toxicity) performance are desired. BMI are expensive in terms of material and processing conditions (high temperature and long curing time) [1], so much effort has been focused on developing new polymeric matrix as benzoxazine which exhibits excellent properties such as near-zero volumetric change upon curing, low water absorption, high char yield, a low coefficient of thermal expansion, an easy thermal curing by ring opening polymerization and, for some benzoxazines, the glass transition temperature (T g ) might be higher than curing temperature [2]. Since a single-layer graphene was firstly isolated in 2004, a worldwide attention in this material has aroused due to its exceptional mechanical and physical properties [3]. One of the most promising applications of graphene is as nanofiller in polymers in order to provide added value properties to the polymeric matrix [4] due to its exceptional specific modulus and mechanical strength, high electrical and thermal conductivity and good chemical resistance [5]. The current work is focused on developing new multifunctional nanocomposites based on the incorporation of graphene nanoplatelets (GNP) in a benzoxazine in order to achieve a matrix with enhanced mechanical and barrier properties as well as high electrical and thermal conductivity. A benzoxazine-based resin supplied by Henkel Corporation has been used for this study. Graphene nanoplatelets, with an average flake thickness lower than 2nm, were purchased to Avanzare (Avangraphene-2). Two nanocomposites with a 0.5 and 2 wt.% of graphene nanoplatelets (BzGrAv0.5 and BzGrAv2 respectively) were manufactured by using a three roll calender. The morphology and the degree of dispersion of GNP in benzoxazine were studied using X- ray diffraction (XRD), where diffraction pattern was obtained for graphene nanoparticles and compared to those from its respective polymer nanocomposites (see Figure 1a). The wide diffraction peak from 10º to 28º is caused by scattering of cured benzoxazine molecules while the tiny shoulder peak found at 26.6º corresponds to the (002) graphitic planes of graphene nanoparticles. The total exfoliation in individual graphene nanolayers is not achieved due to the presence of the graphitic peak in the nanocomposite with a 2 wt.% of GNP. Thermal stability of nanocomposites was studied using thermogravimetric analysis (TGA) in a dry nitrogen environment and results showed a slight increase in both onset and decomposition temperatures. On the other hand, char formation at 800ºC also increases when the amount of GNP in the sample was higher.