硅酸盐水泥基无大孔胶凝材料中金属离子的作用

ROLE OF METAL IONS IN THE MACRO-DEFECT-FREE CEMENTITIOUS MATERIALS MADE WITH ORDINARY PORTLAND CEMENT

在聚丙烯酰胺和硅酸盐水泥基无大孔胶凝材料中掺入无机阳离子对聚合物链和水泥水化物的交联反应有着很大的影响。ＳＥＭ和ＥＤＸ的研究结果表明：水泥水化析出的和掺入无大孔材料中的无机离子都参与形成交联的阳离子－聚合物复合结构。多价阳离子，如Ａｌ和Ｃａ，与聚丙烯酸交联后相互接触形成稳定的分子结构，对水泥的水化反应影响较小。而单价阳离子（Ｋ和Ｎａ）与聚内烯酸反应形成不稳定的盐，加速水泥的水化，并促进水泥水化析出的金属离子与聚合物的交联反应。

Inorganic cations added into polyacrylamide and ordinary portland cement based MDF cementitious materials have significant influence on the cross-linking reaction of chains in polymers and cement hydration.SEM and EDX studies show that both inorganic ions which are released from cement and which are added to the MDF materials participate in the fomation of cross-linked cation-polymer complex structure.Multivalent cations,such as Al and Ca,cross-linked through polyacrylic acids,which then contact mutually,and form stable molecular structure have less influence on the hydration reaction of cement.In the case of monovalent cations(K and Na),they react with polyacrylic acid and form unstable salts which can accelerate hydration of cement,resulting in metal ions released from cement during hydration,catalyzing the cross -linking reaction through the polymers.