Synthesis of a cross-linked polycarboxylate ether superplasticizer and its effects on the properties of cement paste containing montmorillonite

Abstract

The polycarboxylate ether superplasticizer with cross-linked structure (TPCE) was synthesized and characterized in this paper. The adsorption isotherms and kinetics of TPCE on cement and montmorillonite (MMT) were measured and the adsorption layer thicknesses on cement particles were calculated. Its dispersion capability and effects on the hydration of cement were also examined. Results show that TPCE has stronger adsorption, dispersion and dispersion-retention capability on cement containing MMT system than conventional PCE (CPCE). Regardless of PCE types, the maximum d-value of MMT after intercalation is the same, but TPCE shows different intercalation modes from CPCE. The side chains of CPCE initially insert into the galleries of more MMT in monolayer, and further intercalate to form MMT with the maximum d-value. Comparably, MMT exhibits the maximum d-value, even at a low TPCE concentration, but the multi-branches of TPCE decrease the numbers of intercalated molecules.