Preparation And Performance Study Of Temperature-resistant And High-dielectric Barium Titanate/polyarylene Ether Nitrile Organic Film

With the rapid development of electronic industry,small intelligent devices such as semiconductor and capacitor,which are based on dielectric materials,are widely used Therefore,polymer with high energy density,high dielectric constant and low dielectric loss has been widely explored by researchers.Furthermore,the development of microelectronics,aerospace and other fields requires more and more advanced dielectric materials.In addition to high energy density,light weight and other requirements,it also needs to be able to use stably above 150℃.Therefore,development of thermally stabilized polymer dielectric materials is of great significance.Poly(aryl ether nitrile)(PEN),as one of most important poly(aryl ether)special engineering polymers,has been selected as good candidate for preparing polymer dielectric materials due to its excellent thermal stability and dielectric properties(dielectric constant is about 3.5 and the dielectric loss is 0.01-0.02).In addition,barium titanate has been widely used in dielectric composites for its high dielectric constant(～2500),low loss(<0.02)and high thermal stability.Based on this,we here prepared various PEN/functional barium titanate composites.The effect of surface functionalization and synergetic effect of nanoparticles on the dielectric,mechanical,and thermal properties of composites were systematically investigated.The main works contain following three partsFirstly,the BaTiO3@(PDA+KH550)hybrid material was prepared by using dopamine(DA)and silane coupling agent(KH550),which was further compounded with PEN to obtain BaTiO3@(PDA+KH550)/PEN composites.The morphology and structure of BaTiO3@(PDA+KH550)hybrid were tested by FT-IR,XRD,XPS,TGA,SEM and TEM.The dielectric,mechanical,and thermal properties of composites were systematically investigated.It was found that the dispersion of BaTiO3 nanoparticles was greatly improved by the surface modification of PDA and KH550,which resulted in the improvement of heat resistance and dielectric properties of the composite.With addition of 40wt%of modified BaTiO3 nanoparticles,the resulting PEN composite has a higher dielectric constant(10.4)and a lower dielectric loss(0.06)at 1 kHz,compared with pure PEN.With the same loading content,the T10 and T30 of composite were increased by 48℃ and 42℃,respectively.Although the aggregation of BaTiO3 nanoparticles was observed with the high loading content(40 wt%),the tensile strength and modulus of composite were maintained by 77%and 83%,respectively.Secondly,based on the PDA functionalized BaTiO3,BaTiO3@Ag hybrid was prepared by redox reaction,which was further compounded with PEN to obtain BaTiO3@Ag/PEN composites.The morphology and structure of BaTiO3@Ag hybrid were tested and analyzed by FT-IR,XRD,TGA,SEM and TEM.The cross-section SEM,TGA and digital bridge were used to evaluate the properties of PEN composites.The results showed that the dielectric constant of PEN composite material was greatly improved by addition of BaTiO3@Ag hybrid.The dielectric constant of PEN composite with 50 wt%BaTiO3@Ag hybrid reached 27.7,and the dielectric loss is only 0.16.With the same loading content,the T10 and T30 of composite were increased by 57℃ and 72℃,respectively.Thirdly,acidified carbon nanotubes(ac-CNTs)and modified BaTiO3 were compounded with PEN to obtain BaTiO3@(PDA+KH550)/ac-CNTs/PEN composites.The surface modification and structures of acidified carbon nanotubes were tested and analyzed by FT-IR,XRD and Raman spectra.The performance of PEN composite was tested by SEM,TGA and digital bridge.The introduction of acidified carbon nanotubes is conducive to the formation of barium titanate nanoparticles in the energy storage network,which insulates each other and exists in the polymer matrix in the form of micro capacitors,thereby improving dielectric properties.It was found that when the content of acidified carbon nanotubes was continuously increased from 0.5 wt%to 5 wt%,the dielectric constant of the composite was greatly increased,and the dielectric constant reached 150 at 1 kHz(with low dielectric loss of 0.17).Meanwhile,the Tio and T30 of composite were increased by 63℃ and 60℃,respectively.