Gypsum is a kind of air-set cement material, its products have good thermal insulation, sound absorption and fire resistance, and has respiratory function, can adjust the indoor humidity, as a green building material, has been widely used in building decoration and other fields. However, gypsum itself has poor water resistance, great strength loss and easy warping deformation after moisture exposure. The results show that there are three main reasons for the poor water resistance of gypsum material: gypsum has a high solubility in water, at 20 ℃, the solubility of 2.05 gCaSO4 per 1 L of water; The inner surface of the pores of gypsum hardened body has adsorption effect on water. The porosity of gypsum material is large. The researchers synthesized a kind of fluorinated silica emulsion (FSE) waterproofing agent and applied it to gypsum material in order to reduce the inner surface energy of large pores of the gypsum hardening body and improve the compacticity of the gypsum hardening body, so as to improve the bending strength, compressive strength and water resistance of the gypsum material.

The results show that fluorine and silicon monomers are introduced into the synthesized emulsion macromolecules, so the latex film has better hydrophobic properties. The addition of FSE waterproofing agent can change the morphology of gypsum crystals, make the bond between gypsum crystals tight, reduce the intercrystalline pores, so the flexural and compressive strength of gypsum samples can be improved. FSE latex film has the effect of blocking the micro-pores of gypsum hardened body or changing the inner surface energy of large pores of gypsum hardened body, thus preventing the infiltration of water, so the water resistance of gypsum sample doped with FSE waterproof agent is improved.