Preparation And Properties Of Polyethersulfone-silicon Nitride Composites

In the field of electrical and electronic, with the development of electroniccomponents high density and high integrated, the materials of electronic not only havegood thermal conductivity, but also insulation, easy processing, and chemicalresistance. Traditional thermal conductivity of materials cannot meet the requirements.Hence, more and more attention is paid to polymer matrix materials; polyethersulfone(PES) is a thermoplastic polymer material with high performance. However, PES haspoor thermal conductivity. Generally, the filler of high thermal conductivity ceramicare added to improve the conductivity of PES matrix. β-Si3N4has a high thermalconductivity, low coefficient of thermal expansion (CTE), easy storage andtransportation. In this paper，β-Si3N4is filled PES matrix to improve the thermalconductivity and reduce the CTE of composites.The PES/Si3N4composites were prepared by solution mixed and ball-mill mixed.The effect of mixed method, filler content on the microstructure, thermal stabilityproperties, mechanical properties, thermal conductivity of composites werediscussed detailedly by analytical apparatus, such as scanning electron microscopy(SEM), thermogravimetric analyzer (TGA), thermo-mechanical analysis (TMA),thermal conductivity， and mechanical properties analysis.Firstly, the PES/Si3N4composites were prepared with treated by coupling agent bysolution mixed and ball-mill mixed. The results were that the thermal conductivity ofcomposites was increased, the mechanical properties and the CTE were decreased asthe increasing filler content. Considering the practical application of composites, thematerial should have good mechanical properties and high thermal conductivity, sothe maximum filler content were controlled within19vol.%. In19vol.%fillercontent, the thermal conductivity of composites by solution mixed and ball-millmixed reaches0.7W/m·k and0.677W/m·k respectively. Moreover the thermalconductivity of composites increases with increasing temperature. The CTE ofcomposites were decreased by44%(solution mixed) and41%(ball-mill mixed)than pure PES.As the Si3N4added, it decreased the mechanical properties and kept the thermal stability of composites.PES/Si3N4(micron:nano=4:1) were prepared by solution mixed. Studied itsthermal and mechanical properties, found that the different sizes mixed significantlyimprove the conductivity of composites.