The Influence of Vinyl Polymers on the Characteristics of Polymer-Modified Mortars

Seven different polymer latexes, characterized by different resistance to alkaline hydrolysis, were used to produce polymer-modified cement mortars. The following polymers were tested: styrene-butadiene copolymer, vinyl acetate-vinyl versatate copolymer, vinyl acetate-vinyl versatates terpolymer, vinyl acetate-ethylene copolymer, vinyl acetate-vinyl propionate copolymer, vinyl acetate-dibutyl maleate copolymer and vinyl acetate homopolymer. Measurements of compressive strength, dynamic modulus of elasticity, water absorption and bond-strength to a concrete substrate were carried out on the polymer-modified mortars in comparison to a reference mixture without polymers. Infrared and XRD analytical techniques were used to investigate the alkaline hydrolysis of the polymers and cement hydration, respectively. The results indicate that polymers with higher resistance to hydrolysis performed better in terms of higher bond strength to the concrete substrate and lower water absorption of the corresponding mortars.