Comparison of Casein and Polycarboxylate Modified Cellulose Nanocrystals as Superplasticizers in Self-Leveling Mortars

Abstract

In order to replace casein superplasticizer in self-leveling mortars, polycarboxylate grafted cellulose nanocrystals (PC-g-CNCs) have been synthesized and characterized. AFM revealed the spherical and rod-like shape of casein and PC-g-CNCs, indicating that superplasticizers adsorb differently on the surface of cement particles. In ternary binder-based self-leveling mortars, PC-g-CNCs resulted in smoother paste surfaces without bleeding or segregation and improved fluidity retention than casein. It might be due to CNCs’ high water retention capacity, which changed the viscosity of mortar while also facilitating delayed cement hydration. Such a PC-g-CNCs emerge as potential substitute for casein superplasticizer applications.