Both polymerization modification and the use of functional additives for controlling air entrainment inside a polymer were examined for improving their performance in cement matrices. Functional additives were added to acrylic redispersible polymer powders at a glass-transition temperature of −11 oC, and the polymerization method was modified. The physical properties of cement mortars produced with these polymers were evaluated. The performance improved and the average polymer-particle size decreased when using the modified emulsion polymerization method, while the air content in the polymer cement mortars decreased with the use of defoamer as a functional additive. Moreover, better compressive, flexural, and adhesion strengths were achieved, and the use of polymers with improved performance resulted in enhanced waterproofing. Scanning electron microscopy and energy-dispersive spectroscopy confirmed the formation of carbon-based polymer films around the pores and cracks inside the cement mortars.

Keywords: Redispersible polymer powder, Polymerization modification, Functional additives.