摘要本论文采用氯化铵(NH4Cl)与氯化硼(BCl3)为原料合成三氯环硼氮烷(TCB)，再以 TCB 为原料，甲胺为改性取代物，合成 2,4,6-三(甲胺基)硼吖嗪(MAB)，利用 MAB 对 SiC 前驱体聚合物聚碳硅烷（PCS）进行改性，以石英片为载体，采用刷膜法制备碳化 硅陶瓷涂层，并对其进行热转化处理制备碳化硅陶瓷膜。研究碳化硅陶瓷膜的可加工性， 并采用静态/动态氧化法研究碳化硅陶瓷膜的抗氧化性能，得出主要结论如下：TCB 的 改性产物 MAB 通过共混对 PCS 进行改性，保留了其良好的溶解性、流动性，以 MAB 为改性剂加入到 PCS 当中以后，PCS 分子中的 Si-H 键与 MAB 中的氨基发生化学反应， 通过此反应可在 SiC 陶瓷微观结构中引入 B、N 异质元素，有效提高陶瓷膜的性能。以 MAB 与 PCS 的混合比例为 1:1 所制备的碳化硅陶瓷，其抗氧化性能相对较好。81507

毕业论文关键词：聚碳硅烷；碳化硅陶瓷膜；前驱体转化法；抗氧化性能

Abstract In this paper B-Trichloroborazine (TCB) was prepared by the reaction of ammonium chloride (NH4Cl) and boron trichloride (BCl3), and 2,4,6-tris(methylamino)borazine (MAB) was synth esized by substitution of TCB with methyl amine (CH3NH2)。 MAB modified polycarbosilanes (PCS) were synthesized by adding MAB to PCS polymer at ambient temperature, then memb rane materials was prepared on quartz substrates by coating method accordingly。 On this basis silicon carbide (SiC) ceramic coatings were formed by subsquent thermal conversion。  Reacti

vity of MAB and PCS, effect of MAB contents on the PCS structure ， ceramic yield ，

processability and SiC microstructure were investigated by TG, XRD, SEM, etc。 Particularly the oxidation resistance of modified SiC ceramic membranes were studied by static\dynamic oxidation experiments。 Main conclusions could be summed up as follows: PCS modified by b lending with MAB retained fine solubility and liquidity。 Reaction occurred between the Si-H bond in the PCS molecules and the amino group in MAB, which may introduce B and N into t he microstructure of SiC ceramics as heterogeneous elements。 Through this reaction the oxida tion performance of ceramic membrane was effectively improved。 From this perspcetive, whe n the ratio of PCS with MAB to was 1:1 by weight, the oxidation resistance reached optimum performance。

Keywords: PCS,carborundum ceramic membrane,ceramic precursor,oxidation resistance

目录

第一章 绪论 1

1。1 碳化硅陶瓷膜 1

1。1。1 碳化硅的结构和性质 1

1。1。2 碳化硅陶瓷膜的特点和应用 2

1。1。3 碳化硅陶瓷膜的制备方法 3

1。2 有机前驱体转化法及其特点 4

1。2。1 PCS 在有机前驱体法中的应用 4

1。2。2 PCS 的改性 6

1。3 六方氮化硼(h-BN) 7

1。3。1 h-BN 结构、性质、应用及制备方法 7

1。3。2 2,4,6-三(二甲胺基)硼吖嗪 9

1。4 课题的目的及研究意义 9

第二章 实验部分 10

2。1 实验原料及设备 10

2。1。1 实验原料 10

2。2 实验步骤 11

2。2。1 TCB 的合成与提纯