Title: Hybrid Organic-Inorganic Admixtures for Cement Based Materials
Author(s): F. Svegl, L. Skrlep, J. Suput-Strupi, and K. Kalcher
Publication: Symposium Paper
Appears on pages(s): 163-176
Keywords: acrylic latex; bending strength; cement; cement paste; chemical admixtures; concrete; hybrid polymers; polymer-modified mortars; silanes
A new type of admixtures for cement-based materials presented in this work is based on silane-modified acrylic polymers prepared by emulsion polymerization of acrylic monomers and organofunctional silane precursor. The acrylic polymer chain was functionalized with organofunctional silane molecules to build an organic-inorganic polymer structure with terminal siloxane groups. The advantage of this type of polymers over already known polymer modifiers for concrete and mortars is the ability to act as a coupling agent between different phases in the cementitious system. The presence of siloxane groups enables strong chemical interaction among mineral phases of inorganic matrix (cement, aggregate) and direct chemical bonding of organic polymer chain to inorganic phases of the cement based material. The influence of silane-modified acrylic latex admixture on the properties of cement paste and mortar was evaluated and compared to unmodified acrylic latex. Mortars modified with this type of hybrid inorganic-organic polymers showed improved physical-mechanical properties like higher mechanical strength, better adhesion to the substrate, lower shrinkage, better thermal conduction and better resistance to different sources of corrosion.