Evaluation of various cellulose ethers performance in ceramic tile adhesive mortars

Eleven cellulose ethers (CE) were selected and tested in a cement based ceramic tile adhesive (CTA) formulation designed to highlight the effect of the CE on the end-use values of the mortars. Results showed that the end-use values, either in the fresh or hardened state, are strongly influenced by the latex powder/CE choice. This is due to the competitive adsorption between these two components; in the fresh state, it affects the CE concentration in the pore solution and hence the viscosity of the mortar, setting time, and skinning. In the hardened state, when CE films do not prevent evaporation at the tile-mortar interface, adhesion in hot curing conditions is lowered compared to dry tensile adhesion values. Test results showed that CTA formulations should be thought of in terms of the CE/latex powder couple, since interactions between this couple and the cement, strongly influence end-use values of the mortar.