The Application of HPMC in Tile Adhesive

1. What is the Tile Adhesive?

Tile adhesives are compounds used to stick tiles to walls or floors firmly. Fortunately, the application of our MelaColl HPMC in tile adhesive can improve all the features of tile adhesive to satisfy all demands in construction. Therefore, tile adhesive is expected to fix the tiles not just for several years but for decades without failure. It must be easy to use and should not have any gaps between the tile and the substrate.

2. Properties of HPMC

Hydroxypropyl methyl cellulose(HPMC)or hypromellose is a water-soluble non-ionic cellulose ether polymer. The chemical properties can vary according to the degree of substitution and modification. With good performance of thickening, dispersion, emulsification, suspension, adsorption, surface activity, and water retention, our HPMC products are widely used in tile adhesives.

3. Why use HPMC in tile adhesives?

The primary function of HPMC in tile adhesives is water-retaining and thickening. The purpose is to increase the final solidification strength of the tile adhesive, extend the open time, and improve its workability. Usually, when we evaluate the performance of tile adhesive, in addition to its workability and anti-sliding ability, we also pay attention to its mechanical strength and open time.

3.1 Effect to the open time

In a wet mortar, the water in the mortar will evaporate, and then cellulose ether will be gathered on the surface. A film will form on the mortar surface within 5 minutes, which will reduce the subsequent evaporation rate. Therefore, hydroxypropyl methyl cellulose (HPMC) can extend the opening hours.

3.2 Effect to the pull strength

HPMC can also delay the hydration kinetics of cement. This retardation is mainly due to the absorption of HPMC molecules by various mineral phases in the hydrated cement system. Specifically, HPMC molecules are mainly adsorbed on hydration products, such as C-S-H and calcium hydroxide. Besides, due to the increase in the viscosity of pore solutions, HPMC reduces the mobility of ions (Ca2+, SO42-, …) in the pore solution, thereby further delaying the hydration process. Therefore, HPMC in tile adhesive can extend the tensile strength of tile adhesives.