Preparation And Properties Of Graphene Oxide/Polyetheretherketone/Bismaleimide Composites

The progress of materials and industry,more and more stringent requirements on the use of working environment is presented for existing materials with the advancement of technology and the increasingly rapid development of the social circumstance,and the material failures often cause serious damage to product and safety issues.Bismaleimide(BMI)is generally used as aerospace structural materials and matrix materials of microelectronic packaging due to its wave permeability,radiation resistance,heat resistance,low water absorption and good dielectric properties.However,the high crosslinking density leads to brittleness of the molding material and limits a wider range of applications.Therefore,it has become an urgent problem to explore and improve the mechanical properties of BMI resin while improving heat resistance and dielectric properties.In this paper,sulfonated polyetheretherketone(SPEEK)was prepared by using concentrated sulfuric acid and polyetheretherketone(PEEK).The graphene oxide(GO)was obtained by the modified Hummers method,and GO was functionalized with silane coupling agent KH560.Diallyl bisphenol A(BBA)and bisphenol A bisallyl ether(BBE)were reactive diluents,and simultaneously regulated the content of SPEEK and functionalized GO,and obtained a series of BMI-based composite materials by in-situ polymerization.The PEEK and GO and composite materials before and after modification were characterized and tested.The effects of PEEK and GO modification are characterized by Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),EDS spectroscopy,transmission electron microscopy(TEM)and X-ray diffractometry(XRD).The results show that there are obvious sulfonic acid groups in SPEEK,the microstructure changes obviously,and there are many pore structures.GO is successfully graft with KH560 functional groups,the sheet structure is clear with folds on the surface and the number of layers is small.The cross-section of GO/SPEEK/BBA-BBE-BMI composites is observed by SEM.SPEEK exists in porous form and GO is embedded in the middle of SPEEK phase,or SPEEK is coated on GO surface,which is tightly combined with the matrix to form a multi-phase structure with irregular fluctuation.The mechanical properties,heat resistance and dielectric properties of the composites are tested.The results show that the flexural strength,flexural modulus and impact strength of the SPEEK/BBA-BBE-BMI composites reach maximum values of 147.9 MPa,4.2 GPa and 15.7 kJ/mm~2,respectively,when the SPEEK content is 5 wt%,and they are increase by 49.5%,44.8%and 65.3%,respectively,than that of the BBA-BBE-BMI matrix.The thermal decomposition temperature is456℃,which is 15℃higher than that of the matrix.The dielectric constant is significantly reduced,and it is 2.4 at a frequency of 100 Hz.The dielectric loss tangent increases slightly at low frequency and it is lower than the matrix resin in the frequency range of 10~3-10~6 Hz.The flexural strength and impact strength of the GO/BBA-BBE-BMI composites are improve compare with that of BBA-BBE-BMI matrix,but the improvement effect is not as obvious as SPEEK.When the doping amount of GO is 0.5 wt%and the SPEEK content is 5 wt%,the flexural strength and impact strength of the GO/SPEEK/BBA-BBE-BMI composite material reach the maximum,and it increases by 60.1%and 81.1%compare with the BBA-BBE-BMI matrix,respectively.The thermal decomposition temperature increases by 26℃.The dielectric constant decreases slightly and the volume resistivity increases by 1.2times when content of GO is 0.3 wt%.