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,134 北京科技大学学报 第29卷 1998.391:773 Sd,2002,85:2787 [11]Kajii M,Tanaka S,Suzuki Y.et al.A thermally conductive [14]冯春祥，宋永才，谭自烈.元素有机化合物及其聚合物.长沙： SiC polycrystalline fiber and its fiber-bonded ceramic.Ceram 国防科技大学出版社，1999：283 Engin Sci Proc,2001,22(3):471 [15]Matsui S.Paul D R.Pervaporation separation of aromatic/ [12]Kumagawa K,Yamaoka H,Shibuya M,et al.Fabrication and aliphatic hydrocarbons by crosslinked poly methyl acrylate co- mechanical properties of new improved Si-M-C-(O)Tyran- acrylic acid)membranes.J Membr Sci.2002.195:229 no fiber.Ceram Eng Sci Proc.1998.19(3):65 [16]杨南如，岳文海.无机非金属材料图谱手册.武汉：武汉工 [13]Cao F,Kim D K.Li X L,et al.Synthesis of polyalu- 业大学出版社，2000 minocarbosilane and reaction mechanism study.J Appl Polym Production mechanism of polyaluminocarbosilane using aluminum acetylacetonate with polysilacarbosilane ZHAO Dafang,LI Xiaodong,ZHENG Chunman,HU Tianjiao Key Laboratory of Ceramic Fibers and Composites,Institute of Aerospace and Materials Engineering.National University of Defense Technology, Changsha 410073.China ABSTRACT Polyaluminocarbosilane (PACS)is a precursor of ultra-high temperature-resistance Si-Al-C fiber.In order to get a desirable precursor of the fiber,polysilacarbosilane (PSCS)was used to react with alu- minum acetylacetonate (Al(acac)3)to get PACS,the reaction process was traced by FTIR,GPC,H NMR,27 Al-NMR and UV-Vis spectra,and the production mechanism was studied in detail.The result shows that PSCS is a kind of oligomers with Si-Si-Si and Si-C-Si bonds.There are two kinds of reactions during the whole process.One is Kumada rearrangement that Si-Si-Si bond translated into Si-C-Si bond,the other is Al(acac)3 with the silicon carbon compounds.The obtained PACS has a higher relative molecular mass and branching degree because of the cross linkage of Al(acac)3.The crosslink mainly occurs below 330C and above 400C.In PACS,Al is in the state of Si-O-Al. KEY WORDS polyaluminocarbosilane(PACS);production mechanism;silicon carbide fiber;aluminum aceta" lacetonate (Al(acac)3)1998391：773 ［11］ Kajii MTanaka SSuzuki Yet al．A thermally conductive SiC-polycrystalline fiber and its fiber-bonded ceramic．Ceram Engin Sci Proc200122（3）：471 ［12］ Kumagawa KYamaoka HShibuya Met al．Fabrication and mechanical properties of new improved Si—M—C—（O） Tyranno fiber．Ceram Eng Sci Proc199819（3）：65 ［13］ Cao F Kim D KLi X Let al．Synthesis of polyaluminocarbosilane and reaction mechanism study．J Appl Polym Sci200285：2787 ［14］ 冯春祥宋永才谭自烈．元素有机化合物及其聚合物．长沙： 国防科技大学出版社1999：283 ［15］ Matsui SPaul D R．Pervaporation separation of aromatic／ aliphatic hydrocarbons by crosslinked poly （methyl acrylate-coacrylic acid） membranes．J Membr Sci2002195：229 ［16］ 杨南如岳文海．无机非金属材料图谱手册．武汉：武汉工 业大学出版社2000 Production mechanism of polyaluminocarbosilane using aluminum acetylacetonate with polysilacarbosilane ZHAO Daf angLI XiaodongZHENG ChunmanHU Tianjiao Key Laboratory of Ceramic Fibers and CompositesInstitute of Aerospace and Materials EngineeringNational University of Defense Technology Changsha410073China ABSTRACT Polyaluminocarbosilane （PACS ） is a precursor of ultra-high-temperature-resistance Si—Al—C fiber．In order to get a desirable precursor of the fiberpolysilacarbosilane （PSCS） was used to react with aluminum acetylacetonate （Al（acac）3） to get PACSthe reaction process was traced by FTIRGPC1H—NMR27 Al—NMR and UV—Vis spectraand the production mechanism was studied in detail．The result shows that PSCS is a kind of oligomers with Si—Si—Si and Si—C—Si bonds．There are two kinds of reactions during the whole process．One is Kumada rearrangement that Si—Si—Si bond translated into Si—C—Si bondthe other is Al（acac）3 with the silicon carbon compounds．The obtained PACS has a higher relative molecular mass and branching degree because of the cross linkage of Al（acac）3．The crosslink mainly occurs below 330℃ and above 400℃．In PACSAl is in the state of Si—O—Al． KEY WORDS polyaluminocarbosilane （PACS）；production mechanism；silicon carbide fiber；aluminum acetalacetonate （Al（acac）3） ·134· 北 京 科 技 大 学 学 报 第29卷