Effect of surface modification of colloidal particles in polymer latexes on cement hydration. (30th November 2017) - Lu, Zichen
Highlights: Introduction of PEO hairy layer on colloidal particles surface minimizes the retardation effect on cement hydration. Hairy surface does not reduce the hydrolysis rate of acrylate contained in the SA polymers. Hairy surface does not hinder the complexation of carboxyl group with Ca 2+ ions. Hairy surface reduces the adsorption amount of polymer on the surface of cement grains. The reduced adsorption amount of colloidal polymer causes the less retardation effect on cement hydration. Abstract: Two styrene-acrylate (SA) polymer latexes with and without the introduction of PEO hairy layer on the surface of colloidal particles were synthesized. The impacts of the latexes on setting time and cement hydration were evaluated. The hydrolysis of acrylate contained in the polymers and the complexation ability of the generated carboxyl group with Ca 2+ were investigated. It is found hairy layer of colloidal particles minimizes the retardation effect on cement hydration, although it does not mitigate the acrylate hydrolysis and the complexation effect of generated carboxyl groups. Hairy surface reduces the adsorption of polymer on cement surface and consequently leads to less retardation effect on cement hydration.