The effect of superplasticizer molecular weight on its adsorption on, and dispersion of, cement

Assessment of the interaction of polycarboxylate superplasticizers in hydrated lime pastes modified with nanosilica or metakaolin as pozzolanic reactives

“…The extent of the plasticizing action as well as the dispersion maintaining ability is strongly ascribed to structural factors, such as the length of the backbone and of the lateral chains [7]. At the same time, an increase in the molecular weight is expected to enhance the adsorption of the PCE on the binding particles as well as its performance [8,9].…”

Water-soluble sulfonated phenolic resins. III. Effects of degree of sulfonation and molecular weight on concrete workability

“…The cement thereby becomes more negatively charged, which leads to stronger electrostatic repulsion among cement particles. 7 This causes the observed plasticizing effects, and the cement pastes would become less viscous. The reduction in viscosity is responsible for improving fluidity of the resulting cementitious materials.…”

“…5 It is clear that the degree of sulfonation (DS) and molecular weight (MW) are two important properties of admixtures governing the flow prop-erties of cementitious materials. 8,9 Regarding the latter factor, Anderson et al 7 reported that admixtures with higher MW gave greater negative zeta potential, and would, therefore, have a better dispersing capability. Basile et al 10 found that the fluidifying effect for cement pastes could be increased by reducing the content of the monomer and increasing the MW of the condensates.…”

“…This results in the dissociation of the cement agglomerates into primary particles with a significant decrease in the viscosity of the material system. 7 In addition, the polymers would decrease the surface tension of water, produce lubricating films at particle surfaces, or alter the courses of cement hydration. 5 It is clear that the degree of sulfonation (DS) and molecular weight (MW) are two important properties of admixtures governing the flow prop-erties of cementitious materials.…”

Chemical Admixtures of Highway Concrete: Fundamental Research and a Guide to Usage

“…It has been generally considered that the higher the molecular weight, the more fluidity is imparted to the paste [15]. However, Hattori [22] stated that maximum superplasticizer performance was obtained for naphthalene sulfonate polymers with a degree of polymerization of about 10. Andersen et al [32] investigated the effect of the molecular weight of sulfonated polystyrene superplasticizer, and found that the optimum molecular weight to give the maximum adsorption onto a ordinary portland cement was 16 Chiocchio et al [45] claimed that the optimum time to add the superplasticizer was at the beginning of the induction period. They remarked that a large portion of admixture added before the intense first C3 A hydration period was over, was taken up by the early hydration product of the aluminate phase and immediatedly covered by the subsequent hydration product.…”