高岭石/聚苯乙烯插层复合物碳热还原反应制备碳化硅晶须/氧化铝复相陶瓷粉体

PREPARATION OF SILICON CARBIDE WHISKER/ALUMINA COMPOSITE CERAMIC POWDER FROM KAOLINITE/POLYSTYRENE INTERCALATION COMPOUND BY CARBOTHERMAL REDUCING REACTION

以二甲基亚砜(dimethylsulfoxide,DMSO)为插层剂制得高岭石/DMSO插层复合物,将苯乙烯单体与高岭石/DMSO插层复合物进行置换反应,成功地将苯乙烯单体引入高岭石层间,层间苯乙烯在加热条件下聚合,制得高岭石/聚苯乙烯插层复合物。以高岭石/聚苯乙烯插层复合物为原料,在氩气保护气氛下,于1500℃碳热还原反应制备碳化硅晶须/氧化铝(SiCw/Al2O3)复相陶瓷粉体。结果表明:在高岭石/聚苯乙烯插层复合物中,高岭石的层间距由0.717nm扩张到1.130nm,插层率接近100%,插层作用影响了层间羟基基团的振动,使其键合方式发生改变。X射线衍射和扫描电镜分析表明:合成出SiCw/Al2O3复相陶瓷粉体中SiC和Al2O3为主晶相,SiC呈晶须状,其直径≤200nm,长度≥3μm。

Kaolinite/dimethylsulfoxide （DMSO） intercalation compounds were prepared by using DMSO as intercalation agent. Styrene can be intercalated between the layers of kaolinite by replacing intercalated DMSO from the kaolinite/DMSO intercalation compound. It is polymerized by heating to finally prepare a kaolinite/polystyrene intercalation compound. Using kaolinite/polystyrene intercalation compound as raw material, SiCw/Al2O3 ceramic composite powders were prepared by carbothermal reducing reaction at 1 500℃ under an Ar atmosphere. The results indicate that the basal spacing of the kaolinite/polystyrene intercalation compound is increased from 0.717 nm to 1.130 nm; the intercalation of the product approaches 100%, the hydroxyl vibration is affected because of the intercalation impact and its manner of bonding is changed. The synthesized products were characterized by X-ray diffraction and scanning electron microscopy, which indicate that SiC and A1203 are the main crystalline phases and the whiskers are SiC, with diameters ≤200nm and lengths ≥3μm.