Functionalized graphene sheets-epoxy based nanocomposite for cryotank composite application

Multifunctional high performance functionalized graphene sheets (FGSs) based epoxy nanocomposites were investigated to understand the feasibility that these FGSs-epoxy nanocomposites can be applied to cryotank composite applications. The FGSs were successfully synthesized from graphite flakes through preparing graphite oxides by oxidizing graphite flakes first and next, thermally exfoliating the formed graphite oxides. These high performance FGSs were next incorporated into epoxy matrix resin system to generate the uniformly dispersed FGSs reinforced epoxy nanocomposites. The resultant FGSs-epoxy nanocomposites significantly enhanced resin strength and toughness about 3080% and 200700% at room and low temperatures of -130 degrees C, respectively, and reduced the coefficient of thermal expansion (CTE) of polymer resin at both below and above Tg about 25% at loading of 1.6 wt% FGSs, and increased Tg of polymer resin about 8 degrees C at low loading of 0.4 wt% FGSs without deteriorating their good processability. We found that these significantly improved properties of FGSs-reinforced epoxy nanocomposite were closely associated with high surface area and wrinkled structure of the FGSs. The further optimization will result the high performance FGSs-epoxy nanocomposite suitable for use in the next generation multifunctional cryotank carbon fiber reinforced polymer (CFRP) composite applications, where better microcrack resistance and mechanical and dimensional stability are needed. POLYM. COMPOS., 2012. (c) 2012 Society of Plastics Engineers