High-damping polyurethane-based composites modified with amino-functionalized graphene

Abstract

A series of damping composites containing polyurethane/poly (butyl methacrylate) (PU/PBMA) as the polymer matrix and graphene nanoplates (GNP) or amino-functionalized graphene nanoplates (NGNP) as a modifier was successfully synthesized through in situ polymerization. The chemical structure, microphase configuration, damping properties, and thermal stability of the GNP–PU/PBMA and NGNP–PU/PBMA composites were evaluated. Fourier-transform infrared and X-ray photoelectron spectroscopic studies revealed that the amino (–NH2) groups on the NGNP surface presumably reacted with the isocyanate (R–N = C = O) groups of the polymer matrix. This led to robust bonding between the NGNP and the hard segments in PU, resulting in an NGNP/polymer-matrix compatibility superior to that of GNP–PU/PBMA. Structural investigations based on scanning electron microscopy and atomic force microscopy revealed dispersion-state-related differences between the GNP and NGNP in the PU/PBMA matrix; the amino-functionalized GNP were more uniformly dispersed in the polymer matrix than their unmodified counterparts, and microphase separation between the hard and soft segments intensified in NGNP–PU/PBMA, resulting in a greater degree of phase separation, as confirmed by small-angle X-ray scattering analysis. Dynamic mechanical analysis (DMA) revealed that the maximum damping peak (tan δmax) of the composite with 0.7 wt.% NGNP was 22.7% higher than that of pristine PU/PBMA. Additionally, a large independent damping peak appeared in the DMA curve of 0.7 wt.% NGNP–PU/PBMA in the high-temperature range, indicating broadening of the damping temperature range. Moreover, the NGNP incorporation effectively improved the thermal stability of the composite. Overall, this study demonstrates the viability of realizing PU-based materials with excellent thermodynamic and damping properties by incorporating amino-bearing NGNP.

Effective Promotion of Micro Damping of GO Hybrid PU–PF Copolymer Grinding Wheels on Precision Machining

“…The superior mechanical properties and high thermal conductivity of GO led to its excellent tribology applications in polymer nanocomposites [40,41]. The atomically smooth surface and weak van der Waals force between the GO layers eased interlayer sliding and contributed to its self-lubrication characteristics [42,43]. Furthermore, our previous work displayed that a 2D structure of GO with high specific surface area was also good for load transferring [44,45].…”