Why can sodium silicate be used as adhesive?Bonding principle?
Na2SiO3+CO2+H2O=H2SiO3: +Na2CO3 with the carbonization reaction, silica content increased, then the evaporation of the free water and solid silica gel dehydration and condensation sclerosis, its characteristic is: 1. speed. Due to the low concentration of CO2 in air, the carbonization reaction and the solidification process are very slow. 2. volume contraction. 3. low strength. In order to accelerate the condensation, cure rate and strength of water glass, sodium silicate is usually added into the water glass. The formula is Na2SiF6.
Principles of inorganic adhesivesThe chemical bond theory that the adhesive between the adhesive and adherend molecule interactions, and sometimes chemical bonds, such as rubber and metal copper bonding interface and coupling agent on the bonding effect of isocyanate, metal and rubber adhesive interface research showed that chemical bond formation. The strength of chemical bonds is much higher than that of van Dehua; the formation of chemical bonds can not only increase the adhesion strength, but also overcome the disadvantage of adhesion damage due to desorption. However, the formation of chemical bonds is not common, and the formation of chemical bonds must satisfy certain quantized parts. Therefore, it is impossible to make the chemical bond between the adhesive and the adhered material. Moreover, the number of chemical bonds at the unit adhesion interface is much smaller than the number of intermolecular interactions, so the adhesion force from the intermolecular forces cannot be neglected.
As a binder is sodium silicate hydrate, also known as water glass. Because it has the following basic properties: strong adhesive force, high strength, acid resistance and heat resistance, alkali resistance and poor water resistance. Chemical formula Na2SiO3 ? 9H2OThe condensation and solidification of water glass in air is very similar to the solidification and solidification of lime. It is mainly realized by two processes, carbonization and dehydration, crystallization and consolidation
