磁性碳化硅功能陶瓷的制备

采用低分子量的聚硅烷(LPS)与二茂铁合成聚铁碳硅烷(PFCS),后者经高温烧成可制得磁性碳化硅陶瓷,XRD分析表明碳化硅陶瓷具有磁性的原因是由于生成了Fe3Si。铁能够促进β-SiC的形成和生长。     

连续含铁碳化硅纤维及其结构吸波材料的研制

为了研制碳化硅吸波纤维, 首次采用聚二甲基硅烷(PDMS)和二茂铁合成聚铁碳硅烷(PFCS), PFCS经多孔熔融纺丝、 空气不熔化和在N₂中1320℃连续烧成, 可制得连续含铁碳化硅(SiC(Fe))吸波纤维; 用SiC(Fe)纤维与环氧树脂制备的结构材料具有良好的吸波性能。XPS剖面分析、 Raman光谱表明: 纤维表面有一层厚约100nm的富碳层, 由表及里铁的含量逐渐增加; 随着温度的升高游离碳的排列逐渐规整化。研究了碳对纤维性能的影响, 结果表明: 游离碳的存在有利于纤维电阻率的降低, 复介电常数和介电损耗的增大。      

Preparation of continuous Si-Fe-C-O functional ceramic fibers

A new polymer named polyferrocarbosilane（PFCS） was prepared from polydimethylsilane and ferrocene. The spinnability of this polymer can be tailored by controlling the content of ferrocene in the polymer. The prepared polymer was spun into a continuous polymer fiber that was subsequently cured in air and heat-treated finally in N2 up to 1 350 ℃ for conversion into Si-Fe-C-O fibers. The resulted Si-Fe-C-O fibers display low specific resistance and magnetic property due to the existence of Fe, which also reduces the specific resistance significantly to 10^-2Ω·cm at room temperature when the amount of ferrocene in feed is as low as 3.0% （mass fraction）. The resulted Si-Fe-C-O fibers, with C/Si molar ratio of about 1.3 and the maximum Fe content of about 2.0% （mole fraction）, are composed ofβ-SiC and small amount of Fe3Si-like crystalline and have an average tensile strength of about 2.0 GPa.     

连续含铁碳化硅纤维2～18GHz频段雷达波吸收性能探索

采用聚二甲基硅烷(PDMS)与二茂铁合成了聚铁碳硅烷(PFCS)。PFCS经多孔熔融纺丝、空气不熔化和N2中1320℃连续烧成,可制得连续含铁碳化硅(SiC(Fe))吸波纤维,此纤维与环氧树脂制备的结构材料对2～18GHz的雷达波具有较好的吸收。运用元素分析、红外光谱、核磁共振和XPS表征了PFCS的组成结构,结果表明,铁被引入到PFCS中;PFCS的主体结构为—Si—CH2—主链,其中Si上连接有—CH3、—CH2Si—和—H等;二茂铁的存在形式主要是茂环与部分主链Si的结合,因此二茂铁起到了使部分主链交联的作用。HRTRM分析表明连续SiC(Fe)纤维主要由无定型SiCxO4-x、晶态β-SiC和游离碳组成。     

聚铁碳硅烷先驱体的合成工艺研究

本文研究了聚铁碳硅烷的合成,探索了裂解温度、反应温度、二茂铁等因素对合成聚铁碳硅烷(PFCS)工艺的影响;元素分析、红外光谱、氢谱分析表明:铁被引入到聚铁碳硅烷(PFCS)中,PFCS与聚碳硅烷(PCS)的结构相似。