کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9777959 | 1510152 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Preparation of high-temperature stable SiBCN fibers from tailored single source polyborosilazanes
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Bulk SiBCN ceramics derived from polyborosilazanes of the type [B(C2H4SiRNH)3]n (1a, R = CH3; 2a, R = H; C2H4 = CHCH3, CH2CH2) exhibit an exceptional structural stability at high temperature. Therefore, such quaternary systems are of great scientific and technical interest as fibrous reinforcements intended for high-temperature applications. In this context, the design of novel polyborosilazanes, which display properties tailored for the preparation of SiBCN fibers, is studied. Boron-modified polysilazanes of the type [B(C2H4SiRNCH3)3]n (1b, R = CH3; 2b, R = H) are prepared via aminolysis of the tris(dichlorosilylethyl)boranes B(C2H4SiRCl2)3 (1, R = CH3; 2, R = H). It is shown that the functionalisation of the precursors with NCH3 units improves their processability (i.e. solubility) compared to that of their ammonolysed analogs [B(C2H4SiRNH)3]n (1a, R = CH3; 2a, R = H). In addition to the influence of the NCH3 units, the presence of the SiCH3 functions in such polymers offers the best potential for the preparation of fibers by melt-spinning. As-spun fibers are then converted under controlled atmosphere into high-temperature stable SiBCN fibers according to the polymer-derived ceramic route.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 25, Issues 2â3, 2005, Pages 251-256
Journal: Journal of the European Ceramic Society - Volume 25, Issues 2â3, 2005, Pages 251-256
نویسندگان
S. Bernard, M. Weinmann, D. Cornu, P. Miele, F. Aldinger,