Effect of pyrolysis atmospheres on the morphology of polymer-derived silicon oxynitrocarbide ceramic films coated aluminum nitride surface and the thermal conductivity of silicone rubber composites

Amorphous silicon oxycarbide (SiOC) and silicon oxynitrocarbide ( SiONC) ceramic films coated aluminum nitride (AlN) were prepared by using preceramic-polysilazane (PSZ) with dip-coating method, followed by pyrolysis at 700 degrees C in different (air, Ar, N-2 and NH3) atmospheres to converted PSZ into SiOCair and SiONC(Ar, N2 and NH3) ceramic. The existence of amorphous SiOCair and SiONC(Ar, N2 and NH3) ceramic films on AlN surface was characterized by FTIR, XRD and XPS. The interfacial adhesion between silicone rubber and AlN was significantly improved after the introduction of amorphous SiOCair and SiON(Ar, N2 and NH3) ceramic films on AIN surface. It can be observed from AFM that the pyrolysis of PSZ at different atmosphere strongly affected to films morphology on AlN surface as SiOCair and SiONCNH3 ceramic films were more flat and smooth than SiONCN2 and SiONCAr ceramic films. Besides, the enhancement of the thermal conductivity of silicone rubber composites was found to be related to the decrease in the surface roughness of SiOCair and SiONC(Ar, N2 and NH3) ceramic films on AlN surface. This present work provided an alternative surface modification of thermally conductive fillers to improve the thermal conductivity of silicon rubber composites by coating with amorphous SiOCair and SiONC(Ar, N2 and NH3) ceramic films. (C) 2013 Elsevier B.V. All rights reserved.