Abstract:

Potassium silicate gel， which combines high optical transparency at room temperature with excellent foaming capability at elevated temperatures，is an ideal choice for the interlayer material of composite fire-resistant glass.The performance parameters of the foamed gel are key indicators for characterizing the thermal insulation performance of potassium silicate-based laminated glass. In this study， the porosity of the foamed gel was calculated using the Archimedes method. The influence of glycerol content on the foaming performance of potassium silicate gel was investigated using methods including Turbiscan Lab Expert analysis， the heat flow method， and TG-DSC. The results indicate that when the glycerol content ranges from 10% to 20% by mass， the foamed gel exhibits a relatively smaller expansion volume but a relatively higher porosity. At a glycerol content of 15%， phase separation of carbonized organic components begins to occur in the foamed gel， leading to the formation of open pores on its surface. When the glycerol content reaches 20%， severe phase separation of carbonized organics takes place， resulting in poor foaming performance. This is evidenced by a thickness expansion ratio of only about 4 times. Comprehensive comparison shows that at a glycerol content of 10%， the sample demonstrates optimal overall performance： the potassium silicate gel expansion layer achieves a volume expansion ratio of 13.62 times， the risk of compromising the fire resistance integrity of the laminated glass is low， the porosity is 92.23%， and the foam morphology is uniform and dense. Moreover， the thermal conductivity remains low. Under these conditions， both the thermal insulation and foaming performance are at their best.

Key words: potassium silicate gel, glycerol, porosity, foaming volume, thermal conductivity