Steric Hindrance Effect of Polycarboxylate Superplasticizer
The steric hindrance effect of polycarboxylate superplasticizers increases with the length of the side chains. Polycarboxylate superplasticizers with longer side chains exhibit stronger dispersibility. However, when the side chain length exceeds a certain value, it tends to cause curling or collapsing, which weakens the steric hindrance effect at the ends of the side chains. Moreover, polycarboxylate superplasticizers with long side chains have a reduced negative charge density, leading to decreased adsorption on the surface of cement particles and an increase in the plastic viscosity of the slurry.