Effect of Hydrophilic-Lipophilic Balance Values of Macromonomers on the Rheological Properties of Cement Paste and Its Working Mechanism

Abstract The hydrophobic groups in the main chain of polycarboxylate superplasticizers play an important role in the dispersion of cement particles. In this study, a series of macromonomers with different molar ratios of ethylene oxide to propylene oxide (EO/PO) were introduced to modify the molecular conformation of polycarboxylate superplasticizer. Subsequently, the influence of macromonomers with different hydrophilic-lipophilic balance (HLB) values on the solution conformation, surface tension, and absorption behavior of synthesized polycarboxylate superplasticizers (PCE) in a cementitious environment was investigated. Furthermore, the rheological behavior of cement paste with different PCE dosages was investigated. The HLB value of macromonomers showed a good correlation with the viscosity of cement paste. By adjusting the HLB values of the macromonomers, the dispersion ability and viscosity-reducing performance of PCEs can be greatly enhanced.