Effects of Chemical Structure on Adsorption of Polycarboxylate Superplasticizers on Cement Particles

Abstract:

Superplasticizers with various of length of side chains, density of the carboxylic (-COO-) and sulfonic groups (-SO3-) have been synthesized based on different monomers and ratios. The effects of these structural factors on the properties of cement pastes were investigated though measurements of paste fluidity, adsorption amount and Zeta potential (ζ-potential). The results indicated that the higher density of -COO^- and -SO₃^- and the longer of polyoxyethylene (PEO) side chains contributed to the dispersion and adsorption amount of cement pastes in the presence of the same dosage of polycarbosylate superplasticizer. The results indicate that -COO^- and -SO₃^- mainly provide electrostatic repulsion effects and PEO side chains contribute to the steric hindrance repulsion during the process of hydration of cement.

• Periodical: Applied Mechanics and Materials (Volumes 80-81)
• Pages: 185-189
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.80-81.185
• Online since: July 2011
• Authors: Sheng Hua Lv, Rui Jun Gao, Jian Ping Duan
• Keywords: Adsorption, Chemical Structure, Polycarboxylate, Superplasticizer

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