Effect of Density of Acrylic Acid Ester on Sulfonate-Modified Polycarboxylate Superplasticizers on Cementitious Systems

To tackle high viscosity in fresh concretes, especially high-performance concrete, the research of polycarboxylate superplasticizers (PCEs) is relevant. By designing the molecular structure of PCEs, problems such as pumping difficulties in high viscosity of high-performance concrete can be solved. Therefore, in this paper, a suite of novel viscosity reducing PCEs containing sulfonic acid groups and different acrylate densities were synthesized on the basis of inventive molecular structure design, and characterized to determine the predicted structure. The maximum adsorption, the best fluidity, and the Minimum zeta potential value can be seen for PCEs with a small number of ester groups (PCE-MA0.5) due to the combination of the rigidity of its backbone and the density of the adsorption groups. Moreover, the investigation of working mechanism showed the introduction of ester groups can significantly reduce viscosity, but also reduces the adsorption capacity. This research aims to propose a feasible method for synthesizing PCE with superior processability and viscosity reduction capability in cement and concrete.