| Bismaleimide resin?BMI?is a class of thermosetting resins with high heat resistance and excellent processability for use in cutting-edge fields such as aerospace and new energy.However,the development of new materials towards high functionality and compounding,a single BMI resin has been unable to meet stringent requirements,and its cured product has a high crosslink density,big brittleness,and application development is severely restricted.In this paper,diallyl bisphenol A?BBA?and bisphenol A bisallyl ether?BBE?were used as reactive diluents,4,4'-diamino diphenyl methane bismaleimide?BMI?was used as a reactive monomer to synthesize MBAE matrix resin.Polyethersulfone?PES?and sulfonated polyetheretherketone?SPEEK?were used as toughening agents,and functionalized nano-Al2O3@Si O2?KH560-Al2O3@Si O2?was used as modifier to synthesize KH560-Al2O3@Si O2/PES-SPEEK/MBAE composites.Fourier transform infrared spectroscopy?FT-IR?,X-ray diffraction?XRD?,scanning electron microscopy?SEM?,energy dispersive spectrometer?EDS?and transmission electron microscopy?TEM?were used to characterize the modification effect of SPEEK and KH560-Al2O3@Si O2.The results showed that there were sulfonic acid groups in the chain of SPEEK,the microstructure was loose and linear,and the degree of sulfonation was about 41.3%.The KH560-Al2O3@Si O2particles had a clear microstructure and a complete core-shell structure.The inner core was short-fiber Al2O3,and the outer shell was amorphous Si O2,which were connected by chemical bonds.KH560 functional group was successfully grafted on its surface,and the particle packing phenomenon was weakened.The cross-sectional morphology of KH560-Al2O3@Si O2/PES-SPEEK/MBAE composites was observed by SEM.Right amount of PES,SPEEK and KH560-Al2O3@Si O2formed a multi-phase structure in the MBAE matrix,and have good dispersibility.The cross-sectional shape was fish scale,and there were no nanoparticle agglomerates.The porous SPEEK disappeared,the honeycomb PES size was small,and the overall structure was regular.The mechanical,thermal and dielectric properties of the composites were tested.The results show that when the contents of PES,SPEEK and KH560-Al2O3@Si O2were 3 wt%,2 wt%and 3 wt%,KH560-Al2O3@Si O2/PES-SPEEK/MBAE composites had bending strength and impact strength of 173.5 MPa and 22.1 k J/m2,which were 73.7%and 132.6%higher than MBAE matrix.Thermal decomposition temperature was 453.2°C,which was15.1°C higher than MBAE matrix.Dielectric constant both the dielectric loss and the dielectric loss reached a minimum value of 3.4 and 0.0031 at 100 Hz,respectively.The overall performance of the material was improved. |
PDF Full Text Request