水玻璃黏结剂的固化和粉化机理研究

Mechanisms of Solidification and Pulverization of Sodium Silicate Binder

以沙子为骨料,水玻璃作为黏结剂,三氯化铝作为固化剂,制备成大尺寸多孔沙砖,研究水玻璃黏结剂的固化机理和粉化机理。通过采用红外和X射线衍射仪测试在不同环境和不同固化时间黏结剂的结构变化和官能团变化,发现水玻璃凝胶在干燥环境不断脱水,其中的Si—O—Al键含量随时间延长而增加,形成稳定的网状交联结构;在潮湿环境,受到羟基作用使Si—O—Al键断裂而导致黏结剂粉化。

The solidification and powder mechanisms of sodium silicate binder were investigated using aluminum chloride as a curing agent. Through the analysis of functional group change and structure change of water glass binder in the dry and humid environment during different time, it was found that the number of Si-O-Al bond is incr eased as the time increase in dry enviroment, leading to increasing the strength of water glass binder. Whereas the Si-O-Al bond is damaged resulting in the pulverization of water glass binder in the humid environment.