Silver nanoparticles-coated 2D glass-flakes reinforced polyurea composites with high thermal conductivity, acceptable toughness and thermal stability

An effective 2D thermal-conductive filler was prepared by coating glass flakes with silver (Ag-coated-glass flakes) through the electroless plating method for the first time. The XRD, XPS and SEM results showed that the silver completely covered the glass flake, and the silver volume could be controlled by the silver nitrate concentration. When the Ag-coated glass flakes was introduced to polyaspartic acid resin (PAE) matrix, the measurement results indicated that the thermal conductivity of the Ag-coated glass flakes/PAE composite was gradually enhanced with increasing loading of (Ag-coated glass flakes) as well as the volume of Ag on the surface of glass flake. The high thermal conductivities of 0.61–1.15 Wm −1 K −1 were achieved for 1.41–4.58% (vol) (Ag-coated glass flakes/PAE composites. The improvement was ascribed to its formation of continuous and effective 3D heat transfer channels by Ag-coated-glass flakes in PAE matrix. Furthermore, the introduction of low loading of Ag-coated glass flakes into PAE exhibited an enhancement effect on the impact strength. The impact strengths for 2.16% (vol) Ag-coated glass flakes-2 and Ag-coated glass flakes-4 filled PAE composites were increased by 30.5% and 20.3% as compared with pure PAE resin. Besides, the introduction of Ag-coated glass flakes enables the composites with obvious improvements of the degradation temperature, heat deformation, Vicat softening temperature. Therefore, the results of this study suggested an alternative method to fabricate high thermal conductive PAE-based composites with decent toughness and thermal stability. Graphical abstract