Binder distribution in spray-dried alumina agglomerates
Binder distribution in spray-dried alumina agglomerates
复制标题
DOI：
10.1016/s0955-2219(98)00107-1
复制
发表时间：
1998-01-01
影响因子：
5.7
通讯作者：
Baumard, JF
中科院分区：
文献类型：
--
作者：
Baklouti, S;Chartier, T;Baumard, JF
在陶瓷悬浮液的喷雾干燥过程中，有机粘结剂，特别是那些水溶性的粘结剂，往往会随着溶剂的流动而迁移。PVA在氧化铝颗粒表面的吸附等温线表明，与聚甲基丙烯酸铵相比，聚合物的亲和力较低。添加的PVA只有6%(按氧化铝干重计算为3wt%)吸附在氧化铝表面，主要的游离部分，未吸附的粘结剂能够在干燥过程中迁移。聚乙烯醇在氧化铝团聚体和绿色压坯中的分布图像表明，粘结剂的分布不均匀。PVA分离到颗粒表面，导致形成富含聚合物的层。这一层的厚度估计为颗粒半径的几个百分点，其中包含大约50%的引入粘结剂。(C)1998年爱思唯尔科学有限公司。版权所有。
Organic binders, especially those which are water-soluble, tend to migrate with the solvent flow which occurs during the spray-drying process of ceramic suspensions. The adsorption isotherm of PVA on the surface of alumina particles shows a rather low affinity of the polymer when compared to that of the ammonium polymethacrylate. Only 6% of the added PVA (3wt% on a dry weight basis of alumina) was adsorbed onto the alumina surface, and the main fraction of 'free', non-adsorbed, binder was able to migrate during drying. Images of the distribution of the polyvinyl alcohol in the alumina agglomerates and in the green compacts indicate an inhomogeneous distribution of the binder. The PVA segregates to the surface of the granules and leads to the formation of a polymer-rich layer. The thickness of this layer, which contains about 50% of the binder introduced, was estimated to be a few percent of the granule radius. (C) 1998 Elsevier Science Limited. All rights reserved.