文献类型：期刊文献

英文题名：Carborane-Terminated Silicon Arylacetylene Precursor: High Ceramic Yield and Superior Oxidation Resistance

作者：Feng, Xuan[1];Zhang, Wenhua[2];Jiang, Fengguang[1];Liu, Min[1];Zhou, Quan[1]

机构：[1]East China Univ Sci & Technol, Key Lab Specially Funct Polymer Mat & Related Tech, Minist Educ, Shanghai, Peoples R China;[2]Shanghai Composite Mat Technol Co Ltd, Shanghai, Peoples R China

年份：2026

卷号：109

期号：3

外文期刊名：JOURNAL OF THE AMERICAN CERAMIC SOCIETY

收录：;EI(收录号：20261320354618);WOS:【SCI-EXPANDED(收录号:WOS:001720779600001)】；

基金：The authors gratefully appreciate the financial support from the National Natural Science Foundation of China (grant numbers 52473075, 52173074) and the Fundamental Research Funds for the Central Universities (grant number JKD01261701).

语种：英文

外文关键词：carborane; microphase evolution; microscopy; polymer derived ceramics; thermogravimetric analysis TGA

摘要：In this study, a novel carborane-terminated silicon-containing arylacetylene ceramic precursor (CPSA-R) was successfully synthesized, employing dimethyldichlorosilane (DMDCS), methyldichlorosilane (MDCS), and methylvinyldichlorosilane (MVDCS) as silicon sources, with 1-bromomethyl-o-carborane serving as the boron source and m-diethynylbenzene as the crosslinking moiety. The molecular structure of the product was characterized and confirmed by Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (H-1 NMR). The curing mechanism, thermal stability, and ceramization behavior of the precursor were systematically investigated by x-ray diffraction (XRD), thermogravimetric analysis (TGA), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Raman spectroscopy. The results demonstrate that the precursor exhibits excellent solubility, with curing predominantly governed by Si & horbar;C equivalent to C crosslinking. Reactive substituents (such as Si & horbar;H and Si & horbar;CH & boxH;CH2) significantly accelerate the Si & horbar;C equivalent to C reaction and increase the crosslinking density, thereby effectively suppressing rupture of the carborane cage and leading to a ceramic yield exceeding 90% and enhanced thermal stability in TGA. XRD analysis revealed that the derived ceramics remain amorphous at 1200 degrees C, initiate crystallization into SiC at 1400 degrees C, and form a minor amount of B4C at 1600 degrees C. SEM observations showed that with increasing pyrolysis temperature, grains evolve from dense amorphous structures to nearly spherical morphologies, with grain size following the order CPSA-H > CPSA-V > CPSA-J. TEM further confirmed the presence of crystalline SiC and B4C in the pyrolyzed ceramics. XPS results indicated that the intensity ratios of Si & horbar;C/Si & horbar;O and B & horbar;C/B & horbar;O vary with crosslinking density, highlighting the pronounced influence of molecular structure on bond rearrangement, while also revealing that ceramization is jointly governed by carbothermal reduction and bond rearrangement reactions. Raman spectra further demonstrated that the degree of graphitization decreases with reduced carbon content in the side groups, with CPSA-J exhibiting the highest graphitization. Thermal oxidation experiments showed that all three ceramics display a characteristic "weight-gain followed by weight-loss" trend upon heating in air. Among them, CPSA-H exhibits the best oxidation resistance, attributable to its higher SiC and B4C content, which generate dense B2O3 and SiO2 protective layers during oxidation.