摘要本论文首先利用氯化铵(NH4Cl)和三氯化硼(BCl3)在一定的实验条件下制备单体三 氯环硼氮烷(TCB),再以单体 TCB 合成氨基取代产物,进而合成聚合硼氮烷(PBN)。以 聚合硼氮烷为改性剂改性碳化硅前驱体聚碳硅烷(PCS),分别以纯 PCS 和 PBN 改性 PCS 为有机前驱体,通过有机前驱体转化法,进行自发泡,制备纯多孔 SiC 陶瓷和改性多孔 SiC 陶瓷。对所制得多孔陶瓷进行性能表征,研究 PCS 经过 PBN 改性以后得到的有机 前驱体的微观结构,以及其在一定条件下所转化形成陶瓷产物的结构、力学性能和过滤 性能。
研究发现,以 PBN 作为改性剂加入到 PCS 当中以后,PCS 分子中 Si-H 键和 PBN 分子中的-NH2 键发生化学反应,生成小分子气体,通过此反应可在 SiC 陶瓷微观结构中 引入 B、N 异质元素,同时有效提高陶瓷性能。另外,分别以制备的纯多孔 SiC 陶瓷和 改性多孔 SiC 陶瓷作为过滤材料,利用金属铜进行静滴法实验,发现对于熔融金属的过 滤,改性多孔 SiC 陶瓷的过滤性能会得到显著提高。78320
毕业论文关键词:多孔碳化硅,有机前驱体,过滤性能
Abstract In this paper, prepare a monomer-trichloro borazine (TCB)under certain experimental conditions Firstly, ammonium chloride (NH4Cl) and boron trichloride (BCl3), and then the synthesis of amino-substituted monomers TCB product, and then synthetic polymeric borazine (PBN)。 Polymerized borazine as modifier modified silicon carbide precursor polycarbosilane (PCS), respectively, and pure PBN modified PCS PCS organic precursor by an organic precursor conversion method, self-foaming, preparation of pure porous SiC porous SiC ceramics and modified。 On a porous ceramics prepared characterization, microstructure research PCS After a PBN-modified organic precursors, as well as structural, mechanical and filtration properties under certain conditions its conversion to form the ceramic product。
The study found that in order to PBN as a modifier was added to the PCS them later, PCS molecule Si-H bonds and PBN molecule -NH2 key chemical reaction to produce small molecular gas can be introduced by the reaction in SiC ceramics microstructure B, N heterogeneous elements, and effectively improve the performance ceramics。 In addition, they were pure and modified porous SiC ceramics prepared as a ceramic porous SiC filter material, the use of copper metal sessile drop method experiments and found that the molten metal filtration, filtration properties of modified porous SiC ceramics can be significantly improved。
Keywords: Porous silicon carbide,Organic precursors,Filtration performance
目录
第一章 绪论 1
1。1 多孔 SiC 陶瓷 1
1。1。1 SiC 的结构和性质 1
1。1。2 多孔 SiC 陶瓷的特点和应用 3
1。1。3 多孔 SiC 陶瓷的制备 5
1。2 PCS 有机前驱体及其改性 5
1。2。1 PCS 前驱体的结构和特点 6
1。2。2 多孔 SiC 陶瓷的前驱体转化制备技术 6
1。2。3 PCS 有机前驱体及其改性 7
1。3 多孔 SiC 陶瓷的过滤性能及其表征