Multi-Scale Damping of Graphene Foam-Based Polyurethane Composites Synthesized by Electrostatic Spraying

An electrostatic spraying technique was used to synthesize 3D graphene foam (GrF)-reinforced polyurethane (PU) composites. Glass transition temperature (T-g) of PU increased from 120 to 148 degrees C after 3.3 vol% GrF addition. Strong interfacial bonding accounts for the improvement in T-g of PU-GrF composites. Energy dissipation behavior is probed at multiple load scales to examine the intrinsic and structural damping characteristic. Micro-scale damping at 1 mN and 1,000 Hz exhibited loss tangent value (tan delta), which is 200% higher and 3 times faster than PU. Nano dynamic mechanical analysis of PU-3.3 vol% GrF composite demonstrated up to 383% tan delta improvement than of PU at 5 mu N dynamic load. Physical mechanisms including rippling effect and weak van der Waals forces in graphene account for the high energy dissipation of PU-GrF composite. This study suggests that PU-GrF nanocomposites have the potential to serve as a good damping material in vibrating systems. (C) 2018 Society of Plastics Engineers