What method is used for the surface high temperature treatment of silica?




Surface high temperature treatment is to perform high temperature heat treatment on the precipitated silica to remove some molecules adsorbed on the surface of silica, namely water and other low molecular weight adsorbates. As a result of this, partial vulcanization characteristics can be improved, but the effect is not significant. Surface chemical treatment is to use some chemical reagents to react with the surface active silanol groups of silica to improve the affinity and reactivity of silica and polymer compounds. There are many reagents that can chemically treat the surface of silica, and there are various methods for chemical treatment. There are many literatures and patents on this aspect. The following is a brief introduction.

The specific process methods used are:

(1) Steam method: the dry silica is directly contacted with the steam of the organic matter, and the required reaction occurs;

(2) Reflux method: the white carbon black is boiled and refluxed together with the reaction solution, and the desired reaction occurs;

(3) Autoclave reaction method: The silica and the reaction solution are hot-pressed in an autoclave to make the specified reaction occur. The specific chemical reactions used are as follows: as the degree of hydration increases, the isolated silanol groups gradually decrease, while the ortho-type silanol groups gradually increase. The ortho-type silanol group has strong adsorption capacity for water and polar substances.