Fractionated and Recombined Casein Superplasticizer in Self-Leveling Underlayments

Abstract:

Individual casein biopolymers have been fractionated out of the whole bovine casein, and characterized with respect to their specific dispersing performance in cement based self-leveling underlayments (SLUs). In contrast to β- and κ-caseins, α-casein provided excellent dispersing effectiveness as well as unique self-healing effect on the surface of the grout. In order to reproduce the bovine casein, a reconstituted casein sample was prepared by blending the individual biopolymers. Using fast protein liquid chromatography (FPLC), the biochemical composition of recombined casein was determined. Compared with the commercial casein, the reproduced casein superplasticizer exhibited improved dispersing power in SLU paste at the flow time of 0 – 20 min. Furthermore, atomic force microscope (AFM) images revealed the morphology of commercial casein and reproduced casein in alkaline environments. The latter was found to form smaller structure, which explained the improved initial flow of SLU paste. This study suggests that the performance of casein superplasticizer can be modified by recombining the individual casein biopolymers. SLU pastes with different properties may be further achieved by adjusting the biochemical composition of the recombined casein superplasticizer.

• Periodical: Advanced Materials Research (Volume 687)
• Pages: 443-448
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.687.443
• Online since: April 2013
• Authors: Hang Bian, Johann Plank
• Keywords: Admixture, Biopolymer, Casein, Self-Leveling Underlayment, Workability

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