不同引发体系的氧化铝浆料固化过程  

GELATION PROCESS OF ALUMINA SLURRY INITIATED BY VARIED INITIATOR 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：《硅酸盐学报》2008年第7期950-953,共4页Journal of The Chinese Ceramic Society

基　　金：中国科学院知识创新工程青年人才领域前沿项目(SCX200706)

摘　　要：用流变仪测试了氧化铝浆料的流变曲线和固化过程的弹性模量曲线,研究了引发剂对氧化铝浆料固化过程的影响。用于引发浆料中单体(acrylimade and N,N'-menthylene-bis-acrylamide,AM/MBAM)的聚合反应的3种引发体系分别为:过硫酸铵(ammonium persulfate,APS)、过硫酸铵-四甲基乙二胺(APS and N,N,N',N',-tetramethylethylenediamine,APS-TEMED)、偶氮二异丁咪盐酸盐[azobis(2-amidinopropanepane)dihydrochloride,AZAP]。分散氧化铝浆料时,柠檬酸加入量为0.2%(质量分数)可以得到较好的流动性。测试氧化铝浆料固化过程中的弹性模量曲线,研究了氧化铝固含量(体积分数)和温度对固化过程的影响。相对于单体溶液的凝胶过程,浆料固化过程闲置时间明显减少:在低温(25℃),APS-TEMED为引发剂时,氧化铝粉体固含量高于38%的固化闲置时间基本不变,为7.6min;在较高的温度(45℃),APS和AZAP为引发剂时,固含量对固化的闲置时间没有影响,固化的闲置时间分别为15min和7.5min。因此,通过改变温度和引发剂可以控制浆料固化进程。加入氧化铝粉体后得到的浆料固化的闲置时间减小,原因是浆料的容器效应以及颗粒表面的吸附导致单体在氧化铝粉体颗粒表面附近浓度增大。The influence of initiator systems on the gelation process of alumina slurry was studied. Both the rheological properties and the gelation behavior of the slurries were evaluated by a rheometer. Three initiator systems, ammonium persulfate （APS）, ammonium persulfate and N,N,N＇,N＇,-tetramethylethylenediamine （APS--TEMED） redox system and azobis（2-amidinopropanepane） dihydrochloride（AZAP）, were used to initiate the polymerization of monomers （acrylimade and N,N＇menthylene-bis-aerylamide, AM/MBAM） in the alumina slurry. To disperse the slurry, 0.2% （in mass） citric acid is the optimal content to reduce the slurry viscosity. For gelling, the effects of solid loading and temperature on the gelation process with three initiators were investigated via elastic modulus curves. Idle time determined by the abrupt change in the elastic modulus curve is reduced in the presence of alumina powder compared with monomer solution polymerization. With the APS-TEMED redox system, the idle time is a constant 7.6 min as solid loading is higher than 38% （in volume） at 25℃. With APS or AZAP, the idle time is constant （15 or 7.5 min） at 45℃ and solid loading has no effect on the idle time, which is beneficial for controlling the gelation process by temperature and initiators. The reduction of idle time in the presence of alumina powder is attributed to the ＂container＂ effect and the monomer adsorption on the particle surface, which leads to the monomer content increasing around the particle surface.

关 键 词：凝胶浇注成型 氧化铝 固化 引发剂 

分 类 号：TQ174[化学工程—陶瓷工业]