Novel Polycarboxylate Superplasticizer Architectures Enabled by Mechanochemistry

Abstract

The mechanochemical synthesis of polycarboxylate superplasticizers (PCEs) was achieved using a planetary ball mill at ambient temperature. The effects of ball milling parameters, including speed, time, and stop method, on PCE performance, molecular weight, and distribution were investigated to optimize conditions. The experimental results suggest that ball milling impacts PCE molecular weight and distribution, striking a balance between polymerization and mechanical degradation during synthesis. The optimal parameters were found to be 400 rpm, 120 minutes total time, and 30 minutes milling plus 3 minutes rest cycles. Under these conditions, the PCE exhibits excellent dispersibility with a cement paste fluidity of 260 mm. The mechanochemical approach eliminates heating requirements, and also reduces the reaction time from 300 to 120 minutes compared to traditional aqueous synthesis. The optimized PCE demonstrates an increased density of long-side chains, leading to enhanced early strength, heightens adsorption, and diminished zeta potential in cement systems. These characteristics are comparable to traditionally synthesized PCEs. Moreover, at higher dosages, further augmentation of PCE adsorption and increased cement paste fluidity were noted here.

Keywords

mechanochemical / polycarboxylate superplasticizer / fluidity / synthesis efficiency / ball grind

RIGHTS & PERMISSIONS

Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature