共查询到19条相似文献,搜索用时 140 毫秒
1.
2.
3.
聚铝碳硅烷的制备及应用进展 总被引:1,自引:0,他引:1
黎阳 《有机硅材料及应用》2012,(1):41-47
介绍了碳化硅(SiC)陶瓷纤维、含铝SiC陶瓷纤维的特点,综述了用聚碳硅烷、聚硅碳硅烷、聚二甲基硅烷与乙酰丙酮铝反应制备聚铝碳硅烷先驱体的合成方法,聚铝碳硅烷的化学结构及在制备耐超高温陶瓷纤维和发光陶瓷薄膜中的应用,评述了各种制备工艺的优缺点,提出了当前工作中需要解决的问题,并展望了今后的发展趋势。 相似文献
4.
聚甲基硅烷是SiC陶瓷前体的一种,该前体含有大量的活性Si—H键,易于低温固化交联,因此受到了越来越多的关注。本文介绍了聚甲基硅烷主要合成方法,包括Wurtz耦合聚合法、超声合成法、脱氢耦合法和电化学合成法;讨论了聚甲基硅烷的改性方法如热交联改性或化学改性,对改性聚甲基硅烷的性能作了比较,并对今后的研究方向作了展望。 相似文献
5.
先驱体转化含铝碳化硅陶瓷纤维具有高强度、高模量、耐高温、抗氧化等特性,是高温陶瓷基复合材料理想的增强体之一。基于含铝Si C陶瓷纤维的制备工艺路线,从聚铝碳硅烷(PACS)的合成方法及其机理、PACS纤维不熔化处理方法和控制Si(Al)C陶瓷纤维缺陷的研究现状方面综述了先驱体转化含铝Si C陶瓷纤维制备的最新研究进展。讨论了现有PACS合成路线和不熔化处理工艺的优缺点。此外,围绕含铝Si C陶瓷纤维的制备路线,认为后续可持续关注的主要有探索新的PACS合成路线、高效不熔化处理方法和提高Si(Al)C陶瓷纤维力学性能的方法等方面。 相似文献
6.
综述了高陶瓷产率聚碳硅烷、液态聚碳硅烷、改性聚甲基硅烷等新型先驱体聚合物的研究进展,并展望了发展前景。 相似文献
7.
8.
9.
SiC(Nb)陶瓷纤维先驱体聚铌碳硅烷的合成与表征 总被引:2,自引:1,他引:1
为了提高SiC陶瓷纤维的综合性能,利用聚二甲基硅烷热解制得的产物液态聚硅烷(liquid polysilane,LPS)与五氯化铌(NbCl5)反应,制各了含铌SiC陶瓷纤维的先驱体聚铌碳硅烷(polyniobiumcarbosilane,PNCS).研究表明:反应过程中存在LPS裂解重排反应,Si-H键在反应中显示出很高的活性,FNCS分子量的增加是LPS形成的Si-H键与NbCl5发生交联反应的结果,用LPS与NbCl5为原料不但能使铌元素成功地引入到先驱体中并且分布均匀,而且由于其成本比其他原料相对低廉便于大批量合成.利用PNCS制备的Si-Nb-C-O陶瓷纤维平均强度为1.8GPa,平均直径为12 μm,耐高温性能优异. 相似文献
10.
聚碳硅烷一沥青共聚物是制备SiC—C材料的先驱体,具有很广阔的应用前景。这里介绍了聚碳硅烷一沥青共聚物的合成、性能及应用。 相似文献
11.
12.
13.
S. AroatiM. Cafri H. DilmanM.P. Dariel N. Frage 《Journal of the European Ceramic Society》2011,31(5):841-845
RBSC composites are fully dense materials fabricated by infiltration of compacted mixtures of silicon carbide and carbon by molten silicon. Free carbon is usually added in the form of an organic resin that undergoes subsequent pyrolysis. The environmentally unfriendly pyrolysis process and the presence of residual silicon are serious drawbacks of this process. The study describes an alternative approach that minimizes the residual silicon fraction by making use of a multimodal particle size distribution, in order to increase the green density of the preforms prior infiltration. The addition of boron carbide provides an alternative source of carbon, thereby eliminating the need for pyrolized organic compounds. The residual silicon fraction in the RBSC composites, prepared according to the novel processing route, is significantly reduced. Their mechanical properties, in particular the specific flexural strength is by 15% higher than the value reported for RBSC composites prepared by the conventional approach. 相似文献
14.
15.
16.
Masaki Narisawa Takashi Iseki Yoshiro Katase Kiyohito Okamura Kunio Oka Takaaki Dohmaru 《Journal of the American Ceramic Society》2003,86(2):227-233
The pyrolysis of polymethylsilane (PMS) in an argon gas environment with a flow rate of 1 L/min was investigated as a standard pyrolytic process, and the investigation showed SiSi network formation at 573 K. Subsequently, various condensed PMS resins were prepared by adjusting pre-heat-treatment or reflux conditions in the temperature range of 423–723 K. The effect of pre-heat treatment or refluxing on the ceramic yield at 1273 K was quantitatively evaluated. Structural evolution in the PMS resins prepared under various reflux conditions was investigated during pyrolysis up to 1873 K. The X-ray diffraction patterns of the pyrolysis products revealed crystallite growth of β-SiC and silicon at 1273–1473 K. 29 Si solid-state nuclear magnetic resonance with the single-pulse method was also conducted on the pyrolysis products at 1273 K. 相似文献
17.
18.
19.
Microwave Processing of Actively Seeded Precursor for Fabrication of Polymer Derived Ceramics 下载免费PDF全文
Suraj C. Zunjarrao Pawel Dyjak Arif Rahman Raman P. Singh 《Journal of the American Ceramic Society》2016,99(7):2260-2266
An innovative, faster and nonconventional processing technique is demonstrated for preparing silicon carbide‐based ceramics derived from polymer precursor. The technique is based on microwave‐induced pyrolysis of an actively seeded, high‐purity preceramic polymer that leads to rapid fabrication of silicon carbide components. It is successfully demonstrated that it is feasible to carry out microwave‐induced pyrolysis by seeding the polymer precursor with very low volume fractions of micrometer and nanometer‐sized metal and dielectric fillers. This process allows for rapid, net‐shape, and potentially low‐cost fabrication of silicon carbide‐based materials. Mechanical properties and microstructure of the silicon carbide‐based composites fabricated using this process are characterized. 相似文献