Graft Polymerization of Acrylamide from Ultrafine Silica Particles by Use of a Redox System Consisting of Ceric Ion and Reducing Groups on the Surface
Graft Polymerization of Acrylamide from Ultrafine Silica Particles by Use of a Redox System Consisting of Ceric Ion and Reducing Groups on the Surface
复制标题
利用二价铈离子和表面还原基组成的氧化还原体系接枝聚合超细二氧化硅颗粒丙烯酰胺
DOI：
10.1295/polymj.21.475
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发表时间：
1989
期刊：
影响因子：
2.8
通讯作者：
M. Shimomura
中科院分区：
文献类型：
--
作者：
N. Tsubokawa;K. Maruyama;Y. Sone;M. Shimomura
研究了超细二氧化硅表面的自由基接枝聚合。由CeO+和带有还原基团的二氧化硅颗粒组成的氧化还原体系能够引发丙烯酰胺(AAM)的自由基聚合。用3-缩水甘油基丙基三甲氧基硅烷在水中酸性条件下对二氧化硅表面进行处理，实现了表面醇羟基的引入。通过表面硅醇分别与3-氨丙基三乙氧基硅烷或3-巯丙基三甲氧基硅烷反应，在二氧化硅表面引入氨基或巯基。氧化还原体系的引发能力随二氧化硅表面还原基团的不同而不同，大小顺序为：醇羟基<；氨基<；在上述氧化还原聚合中，基于聚合物与醇羟基、氨基或巯基反应形成的自由基的扩散，将聚丙烯酰胺接枝到二氧化硅上。二氧化硅接枝率达到25%左右。氧化还原接枝聚合得到的二氧化硅在水中具有稳定的胶体分散性。
Radical graft polymerization from ultrafine silica surface was investigated. A redox system consisting of ceric ion and the silica particles carrying reducing groups, such as alcoholic hydroxyl, amino, and mercapto groups, was capable of initiating the radical polymerization of acrylamide (AAm). The introduction of alcoholic hydroxyl groups onto the surface was achieved by the treatment of the silica with 3-glycidoxypropyltrimethoxysilane in acidic condition in water. Amino or mercapto groups were introduced onto the silica by reactions of surface silanol groups with 3-aminopropyltriethoxysilane or 3-mercaptopropyltrimethoxysilane, respectively. The initiating ability of the redox system changed, depending on the reducing groups on the silica surface, in the following order: alcoholic hydroxyl group<amino group<mercapto group. In the above redox polymerization, polyacrylamide was grafted onto the silica based on the propagation of the polymer from the radicals formed by the reaction of ceric ion with alcoholic hydroxyl, amino, or mercapto groups. The percentage of grafting onto the silica reached about 25%. The silica obtained from the redox graft polymerization gave a stable colloidal dispersion in water.