Preparation And Characterization Of Epoxy Resin Based Composites With High Toughness And Thermal Conductivity

Owning to excellent performance of thermosetting resin,Epoxy resin(EP)has good physical and mechanical properties,excellent insulation performance,low raw material price,and has been widely used in many fields.However,its cured product is brittle,has low impact resistance and poor thermal conductivity,which limits its application in the field of electronic packaging.How to effectively improve the toughness and thermal conductivity of the cured product and maintain its inherent excellent properties has always been a challenge that researchers need to solve.Herein,a series of poly(n-butylacrylate)/poly(methylmethacrylate)-co-glycidyl methacrylate core-shell structured particles(PBMG)were prepared via seed emulsion polymerization to toughen the epoxy resin.Hexagonal boron nitride(h-BN)was modified by wet ball milling combined with sonication(modified BN named as MBN)to improve the thermal conductivity of epoxy resin.The gravimetric method was used to determine the instantaneous conversion and overall conversion rate of monomers during the emulsion polymerization.The size and distribution of the core-shell structured particles were measured by the dynamic light scattering analyzer(DLS).The inner structure and surface morphology of the core/shell particles was observed by transmission electron microscopy(TEM)and scanning electron microscopy(SEM).The morphology and structure of the BN particles was characterized by scanning electron microscopy(SEM),transmission electron microscope(TEM),X-ray diffraction(XRD)and Raman microscope.The mechanical properties of epoxy resin composites were tested by universal testing machine and an impact testing machine.The compatibility and thermal stability of the EP/PBMG/BN composites were characterized by dynamic thermomechanical analyzer(DMA)and thermogravimetric analyzer(TGA),respectively.According to the above researches,it was found that the unnotched impact strength of EP/PBMG blends reached 40.65KJ/m~2 at 5wt%of PBMG particles added to EP matrix,which was 3.39 times higher than that of pure epoxy resin(11.98 KJ/m~2).On this basis,the thermal conductivity of EP/PBMG/MBN composites was 0.517W/(m?K)at the loading of 10wt%MBN,which was 171%higher than that of pure EP.Meanwhile,the unnotched impact strength of EP/PBMG/MBN composites was 2.33 times than that of pure epoxy resin.At the same time,the thermal stability and insulation of composites are still comparable to pure EP.In summary,the EP/PBMG/MBN composites prepared in this experiment has excellent thermal conductivity and impact resistance,which is expected to be applied in the field of electronic packaging.