SiC凝胶浇注成型:不同引发剂引发浆料固化  

Gelcasting of SiC:Gelation Process with Three Initiation Systems

作　　者：董满江[1] 毛小建[1] 张兆泉[1] 刘茜[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《材料导报（纳米与新材料专辑）》2008年第1期385-387,403,共4页

摘　　要：研究了SiC凝胶浇注成型工艺中,不同引发体系引发浆料固化过程的流变特性,发现SiC粉体对丙烯酰胺(AM)自由基聚合存在阻聚作用。引发剂体系分别为过硫酸铵(APS)、过硫酸铵-四甲基乙二胺(APS-TEMED)氧化还原体系和2,2-偶氮[2-(2-咪唑啉-2-基)丙烷]盐酸盐(AZIP·2HCl)。3种引发剂引发的浆料固化过程中均存在阻聚作用。AZIP·2HCl引发时,阻聚作用尤为明显,浆料在120min内不能完全固化。烧结助剂的加入可降低阻聚作用对浆料固化的影响,但浆料仍需较长的时间才能完全固化。煅烧处理可消除粉体的阻聚作用,表明粉体表面的不明有机物可能是阻聚作用的原因。对比3种引发体系引发浆料固化过程的流变曲线,得出APS-TEMED是SiC凝胶浇注成型的理想引发体系的结论。The gelation behaviors of SiG slurry with three initiation systems in gelcasting process are studied. An inhibition of SiC powder in the gelation process is observed with all initiators. Three initiation systems used to initiate the polymerization of acrylamide（AM） in the slurry are ammonium persulfate（APS）, ammonium persulfate and N, N, N′, N′ ,-tetramethylethylenediamine redox system （APS-TEMED）, and 2, 2CAzobis [2-（2-imidazolin-2-yl） propane] dihydrochlorid（AZIP · 2HCI）. The idle time of gelation process is delayed with increasing solid loading which indicates that the polymerization in the slurry is inhibited by SiC powder. The effect of inhibition on the gelation with AZIP · 2HCI initiator is critical and the slurry can not be solidified within 120 min. The inhibition on gelation with AZIP· 2HCI initiator can be bated by the addition of sintering agent and the slurry can be solidified within 120min. The gelation of SiC calcined under 400＂C shows no inhibition in the process with AZIP · 2HCl,which means that the polymerization is inhibited by the organic components on the SiC particle surface,. Compared with other initiators, APS-TEMED is the optimized initiator in the gelcasting of SiC and the slurry can be solidified within 40min at 55℃. gelcasting, SiC, initiation systems, gelation, inhibition

关 键 词：凝胶浇注成型 SIC 引发体系 固化 阻聚 

分 类 号：TQ174.6[化学工程—陶瓷工业]