Preparation and characterization of poly-carboxymethyl-β-cyclodextrin superplasticizer

A new superplasticizer of poly-carboxymethyl-β-cyclodextrin (PCM-β-CD) was prepared by ring-opening polymerization of epoxy chloropropane and CM-β-CD using sodium hydroxide as initiator. The structure of PCM-β-CD was characterized by FTIR and NMR as well as GPC. The performances of the CM-β-CD were tested by measuring paste luidity, setting time, adsorption and zeta-potential. The result showed the performances of PCM-β-CD closed to the control polycarboxylate superplasticizer (PCs) used in this study, especially the fluidity loss is smaller and the setting time is longer than the PCs. The reason might be the synergism of the steric hindrance with the hollow truncated cone and the electrostatic repulsion from –COO− groups. The mechanism of dispersion and retardation by PCM-β-CD was elucidated based on the results of adsorption properties and zeta‐potential of the cement particles. The study offers a new approach to synthesize superplasticizer based on β-CD and an alternative to concrete engineering.