Effect of polymerizable ionic surfactant in the acrylic latex additive on advanced properties of Portland cement-based mortars

Abstract

One of the current trends in the construction industry is the development and application of innovative, durable, and environmentally friendly cementitious mortar materials. Because of the negative bubble-forming effect of traditional latex polymer additives used in a (siliceous) cementitious mortar matrix, causing the deterioration of physico-mechanical performance, a new environmentally friendly acrylic latex additives with decreased bubbleformation was developed and experimentally verified. The emulsion polymerization was performed using a polymerizable surfactant that becomes covalently anchored to polymer particles. During mortar processing, surfactant desorption from the surface of latex polymer particles was avoided, preventing air entrainment and limiting additional environmental pollution. The positive effect of the novel latex additive resulted in the improvement of flexural and compressive strengths of Portland cement-based mortars compared to compositions prepared with a standard latex additive (comprising traditional non-polymerizable ionic surfactant), wherein these values were found to be higher by 1.9 and 2.0 MPa %, respectively, at 0.2 % by mass dosages of the latex additive. Moreover, the novel polymer additive positively reduced water ingress into the mortar structure, suggesting its potential in high-performance water-loaded applications. In this way, the developed mortars containing the novel acrylic latex additive provided not only products with lower sorptivity but, at the same time, led to cementitious structures with enhanced mechanical performance for specific water-loaded applications.