Design of polymeric Si-B-C-N ceramic precursors for application in fiber-reinforced composite materials
Design of polymeric Si-B-C-N ceramic precursors for application in fiber-reinforced composite materials
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DOI：
10.1021/cm001031w
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发表时间：
2000-08-01
影响因子：
8.6
通讯作者：
Aldinger, F
中科院分区：
文献类型：
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作者：
Weinmann, M;Kamphowe, TW;Aldinger, F
讨论了一类新型Si-B-C-N复合材料聚合物前驱体的合成、详细的光谱表征、聚合物到陶瓷的转化以及高温行为。标题化合物[B（C2 H4-（SiRR 2）-R-1-C2 H4-SiHNH）（3）]（n）（C2 H4 = CHCH 3，CH 2CH 2; 5a：R-1，R-2 = H; 5 b：R-1 = H，R-2 = CH 3; 5c：R-1，R-2 = CH 3）是专门为制备陶瓷薄膜和纤维增强陶瓷复合材料基体而设计的。B = CH 3。它们是通过低聚乙烯基硅氮烷[（H 2 C =CH）SiH-NH]（n）（4）与一般类型B的三（异羟甲硅烷基乙基）硼烷（（C 2 H 4 SiHRR 2）-R-1）（3）（C 2 H 4 = CHCH 3，CH 2 CH 2; 3a. R-1，R-2 = H; 3b：R-1 = H，R-2 = CH 3; 3c：R-1，R-2 = CH 3）在没有催化剂和/或溶剂且没有副产物形成的热诱导氢化硅烷化反应中进行。如热重分析（TGA）所示，5a的陶瓷产率为83%，5 b的陶瓷产率为82%，5c的陶瓷产率为63%。在氩气气氛中进行的所获得的非晶陶瓷材料的高温TGA显示出高达2000 ℃的对源自Sb的材料6 b的降解的热稳定性。相比之下，从5a获得的6a材料在1850摄氏度左右分解。最不稳定的是6c陶瓷，它在1450摄氏度分解。通过X射线衍射（XRD）在1400-2000摄氏度的温度范围内研究6a-6c的微观结构发展，表明对于6a，在1700摄氏度下形成优先结晶的Cr-碳化硅，对于6 b，在1500摄氏度下形成优先结晶的Cr-碳化硅，并且对于6c，在1600摄氏度下形成优先结晶的Cr-碳化硅。此外，在6a的XRD图案中观察到较不强烈的反射，这是由β-氮化硅的形成引起的。
The synthesis, detailed spectroscopic characterization, polymer-to-ceramic conversion, and high-temperature behavior of a new class of polymeric precursors for Si-B-C-N composites are discus se d. The title compounds [B(C2H4-(SiRR2)-R-1-C2H4-SiHNH)(3)](n) (C2H4 = CHCH3, CH2CH2; 5a: R-1, R-2 = H; 5b: R-1 = H, R-2 = CH3; 5c: R-1, R-2 = CH3) were designed especially for the preparation of ceramic films and fiber-reinforced ceramic composite matrixes. They are obtained in quantitative yields by the reaction of oligovinylsilazane [(H2C=CH)SiH-NH](n) (4) with tris(hydridosilylethyl)boranes of general type B((C2H4SiHRR2)-R-1)(3) (C2H4 = CHCH3, CH2CH2; 3a. R-1, R-2 = H; 3b: R-1 = H, R-2 = CH3; 3c: R-1, R-2 = CH3) in a thermally induced hydrosilylation reaction without catalyst and/or solvent and without the formation of byproducts. Ceramic yields are 83% for 5a, 82% for 5b, and 63% for 5c as shown by thermogravimetric analysis (TGA). High-temperature TGA of the as-obtained amorphous ceramic materials, carried out in an argon atmosphere, reveals a thermal stability toward degradation of the Bb-derived material 6b up to 2000 degrees C. In contrast, the 6a material, which was obtained from 5a, decomposes around 1850 degrees C. The least stable is the 6c ceramic, which decomposes at 1450 degrees C. The microstructure development of 6a-6c was investigated in the temperature range of 1400-2000 degrees C by X-ray diffraction (XRD), indicating that preferentially crystalline cr-silicon carbide is formed at 1700 degrees C for 6a, 1500 degrees C for 6b, and 1600 degrees C for 6c. In addition, there are less intensive reflections observed in the XRD patterns of 6a, caused by the formation of beta-silicon nitride.