Preparation And Properties Of Organic/inorganic Hybrid Materials For High Temperature Environments

The materials used at high temperature(?1000?)should have special high temperature resistance.The common high temperature resistant materials are ceramic materials with the phosphate or silicate as the carrier.However,there are fewer types of resin carriers for the inorganic materials,which leads to the helplessness for some performance requirements.Although the heat resistance of organic resin carrier is not as good as that of phosphate and silicate,its better molecular designability has better adaptability for the performance.The high temperature resistant materials with organic carriers have become a new research direction.In this thesis,the AG-80 epoxy resin is used as the organic carrier to prepare the organic/inorganic hybrid materials,and the dosage and selection of the components of the hybrid materials are discussed in detail.The IR is used to analyze the structure of the synthesized methyl phenyl silicon intermediate and the silicone modified AG-80;The TG and SEM are used to comprehensively analyze the properties of the modified fillers,modified carbon fibers,and hybrid materials.Finally the high temperature resistance of organic/inorganic hybrid materials is evaluated.The molecular structure of the modified silicone intermediate is designed considering the compatibility between the silicone and AG-80 resin.Calculated by the Carothers gel method and Flory statistical method,the theoretical amount of the silicone intermediate for the modified AG-80 producing gel is predicted.The influence of the amounts of different organosilicon intermediates on the bonding properties,mechanical properties and heat resistance of the modified AG-80 resin is studied.The results show that an appropriate amount of organosilicon is beneficial to improve the adhesion,strength and heat resistance of AG-80.The final selection of the amount of silicone intermediate is 20%of the molar amount of AG-80 resin,and the overall performance of the modified AG-80 is the best.The effects of Al₂O₃,Si O₂,MgO,ZrO₂ before and after the hydroxyl modification on the compatibility and high temperature resistance of the hybrid material system are studied,and it is found that the hydroxyl modification is beneficial to promote the compatibility of the system,but it is not conducive to the high temperature resistance of the system.The effect of carbon fiber plasma treatment time on the strength of the hybrid material is studied.The results show that the polar treatment of carbon fiber can promote the compatibility of the material system,and for the strength of the hybrid material,it has the best plasma body processing time.The Al₂O₃,SiO₂,MgO,ZrO₂,SiC,ZrC,Si₃N₄,AlN is selected as the high temperature resistant fillers,and the high temperature resistant fillers which are suitable for this hybrid materials system are screened.And a high-temperature resistant compound filler which can be sintered and formed for this system has been found.The influence of the thermal weight gain,density and dosage of the compound filler on the thermal weight loss of the system is comprehensively analyzed,and the type and dosage of the high temperature resistant compound filler is finally determined.According to the different ratios of length to diameter and dosage of carbon fiber,the short fiber type and long fiber type carbon fiber reinforced organic/inorganic hybrid materials are prepared respectively.The effect of different heat treatment time on the strength of hybrid materials at 1000?is studied.The TG test,SEM analysis and physical observation for the hybrid materials before and after the heat treatment are carried out,which proves that the prepared organic/inorganic hybrid material has excellent performance at high temperature(?1000?).