Thermal Characterization of Phenylethynyl-TerminatedPolyimide Nanocomposites Reinforced with Expanded Graphite

摘要

The thermal expansion behavior of intercalated graphite flake to the exfoliatedgraphite flake has been microscopically and thermomechanically demonstrated in real-time,showing dramatic linear expansion with the formation of nanoplatelets below 300°C. Thedynamic mechanical properties, thermal expansion, glass transition behavior and thermalstability of the PETI-5 composites nanoreinforced with expanded graphite (EG) having differentaverage particle sizes (1~19 μm size) and nanoparticle content (1~20 wt%) have been studied.The result indicates that PETI-5/EGV composites have greater storage modulus, lower CTE andhigher thermal stability, especially at high concentration of EGV (~1 μm), than PETI-5/EGUand PETI-5/EGB composites with a relatively larger size of EG (~19 μm and ~7 μm). Thethermal properties significantly depend on the concentration and size of the EG nanoplatelets.