Influences of soluble salts on adsorption properties of polycarboxylate superplasticizers

Polycarboxylate (PC) superplasticizers with different chemical structures were synthesized through free radical co-polymerization reaction. A total organic carbon analyzer was used to investigate adsorption behaviors of PCs, and to evaluate influences of soluble salts on absorption properties of PCs. It is found that adsorption ratios of PCs on cement particles decrease greatly with the addition of Na₂SO₄; the adsorption ratio of ethers PC with Hydroxyethyl methacrylate (HEMA) group first increases then decreases with the addition of NaCl; the adsorption ratio of esters PC with short side chains first decreases then increases, while the adsorption ratio of ethers PC with HEMA group decreases with the addition of CaCl₂; the adsorption ratio of esters PC with short side chains decreases with the addition of Ca(NO₃)₂; AlCl₃ causes the decrease of the adsorption ratio of ethers PC with HEMA group.