Preparation And Performance Study Of Organic-inorganic Hybrid Heat-resistant Oxidation, Wave-transmitting Phthalonitrile Resin

With the development of high technology aerospace industry,the material should improve properties to meet the requirements.Advanced polymer composite has been used widely as a new high performance material because of their low density,good processability and superior mechanical strength.Among the matrices of resins,phthalonitrile resins,which has been widely applied in the fields of aerospace,ship,machinery and electronic,was one class of thermosets with excellent heat-resistance,outstanding chemical stability,flame retardancy and low water-absorption.In this paper,the introduction of fluorine could make the excellent dielectric properties.The formation of organic-inorganic hybrid structure and the incorporation of inorganic particle confers the novel resin with thermostability,low dielectric system and excellent thermal stability.But so far,most of the phthalonitrile resins have poor thermo-oxidative stability and dielectric property,thus these shortcomings limit the application of the material.In this paper,a new type of high-temperature resistance of phthalonitrile resin with introducing fluorine silicon and inorganic particles was prepared.First,the phthalonitrile resins?HPN?were prepared by blending fluorine-containing phthalonitrile monomer?FAPN?,low-melting point phthalonitrile monomer?6FDCN?,and4-amino-4-?3,4-dicyanophenoxy?phenyl?2P?.The processability,thermal stability and moisture-resistant properties of the resin was studied by adjusting the ratio of FAPN,6FDCN and 2P.Finally,the ratio of FAPN,XDCN and 2P was optimized to 9:1:0.7 and the resin was named HPN81.In this paper,we choose inorganic particles and organic modifier to continue to improve the performance of the resin?HPN?.The inorganic particles include boron nitride?BN?,silica?SiO₂?,amino-containing silica?SiO₂-NH₂?and aluminum trioxide?Al₂O₃?.They was characterized by laser particle size meter and FT-IR.The organic modifiers carbonborane?BC?and silicon hybrid poly?arylene ether nitrile?oligomers containing fluorene moiety-phthalonitrile?BPSiPEN?were characterized by infrared spectroscopy,gel osmotic chromatography and composition analysis.Three kinds of novel resin systems were obtained by adjusting the formula,optimizing reaction parameters and adding the fillers.They are Al₂O₃-phthalonitrile?Al₂O₃-FAPN?,carborane-phthalonitrile?BC-FAPN?and silicon hybrid poly?arylene ether nitrile?oligomers containing fluorene moiety-phthalonitrile?BPSiPEN-FAPN?,respectively.The chemical structure,curing behavior,processing properties,thermal stability,dielectrical property and moisture-resistant performance were characterized in detail.The results are as follows:1.Blending strategy was applied to prepare Al₂O₃/phthalonitrile hybrid resins,as expected,an incorporation of increasing weight percentages of Al₂O₃/phthalonitrile hybrid resins significantly reduces the value of dielectric constant up to 30wt%of phthalonitrile?k=1.81?.2.Blending strategy was applied to prepare BC/phthalonitrile hybrid resins,the BC reduced the activation energy.The cured BC/phthalonitrile resins exhibited a lower dielectric constant?3.3?,a lower weight loss of thermal cycle?0.6%?.3.Blending strategy was applied to prepare BPSiPEN/phthalonitrile hybrid resins,the blending temperature was reduced from 160?to 150?.Compared with the phthalonitrile resins system,the cured BPSiPEN/phthalonitrile hybrid resins exhibited lower weight loss of thermal cycle?1.07%?,dielectric constants?3.25?,dielectric loss?0.09?.