The principle of water retention of HPMC

When cellulose ethers coexist in wet mortar, some data models show that cellulose ethers are more present in the interstitial liquid and have a greater impact on the viscosity and setting time of the mortar. The surface tension of cellulose ether is larger than that of rubber powder, and more cellulose ether enriched on the mortar interface will be beneficial to the formation of hydrogen bonds between the base surface and cellulose ether.

In wet mortar, the water in the mortar evaporates, and the cellulose ether is enriched on the surface. A film will be formed on the surface of the mortar within 5 minutes, which will reduce the subsequent evaporation rate. As more water is evaporated from the thicker mortar, Part of it migrates to the thinner mortar layer, and the film formed initially partially dissolves. The migration of water will bring more cellulose ethers to be enriched on the mortar surface.