Effects of polycarboxylate superplasticizer equipped with β-cyclodextrin as the terminal group on the fluidity of montmorillonite-containing cement paste

Abstract

In this study, β-Cyclodextrin (β-CD) as the terminal group was grafted on polyoxyethylene (PEO) via click reaction for preparing monovinyl β-Cyclodextrin monomer (β-P). Then β-P was employed to synthesize a polycarboxylate superplasticizer with β-CD grafted on the side chain [PAA-g-(β-P)_nHPEG]. The functional groups, molecular weights, and molecular weight distributions of synthesized copolymers PAA-g-(β-P)_nHPEG were characterized by Fourier transform infrared spectra (FT-IR), ¹H nuclear magnetic resonance spectroscopy (¹H NMR), and gel permeation chromatography (GPC). The dispersion performance of PAA-g-(β-P)_nHPEG in cement paste containing montmorillonite (MMT) clay was tested. Sorption measurement and X-ray diffraction (XRD) analysis revealed that the PAA-g-(β-P)_nHPEG intercalated less into the interlayer space of MMT than PAA-g-HPEG only with PEO as the side chain. β-CD as the terminal group grafted on the end of the side chain of PCE effectively hindered PCE sorption on MMT and enhanced the clay-tolerance property of PAA-g-(β-P)_nHPEG. This study offered a new idea in designing polycarboxylate superplasticizers to lower their clay sensitivity.

Graphical Abstract

Keywords:

• Polycarboxylate superplasticizer
• β-Cyclodextrin
• click reaction
• sorption
• clay tolerance property

Declaration of competing interest

The authors report no declarations of interest.

Additional information

Funding

Thanks for the financial support from the National Natural Science Foundation of China (51961135202).