Synthesis of polycarboxylate superplasticizer modified by self-made functional monomer for improving clay tolerance

Abstract

Polycarboxylate superplasticizer (PCE) is commonly sensitive to clay minerals, so this paper proposes synthesizing several clay-resistant superplasticizers (CR-PCE) using a novel self-made functional monomer. The resulting functional monomer and superplasticizers were characterized by Fourier transform infrared spectrophotometry (FT-IR) and gel permeation chromatography (GPC). The results show that the CR-PCE samples exhibit a better dispersion performance as compared to the conventional polycarboxylate superplasticizer (C-PCE) sample in the montmorillonite-bearing cement pastes. The adsorption amount of the CR-PCE samples on the Mmt was investigated by Ultraviolet-visible spectrophotometry (UV), and it was found that the CR-PCE samples have a lower clay sensitivity compared with the C-PCE sample. The X-ray diffraction (XRD) results of the montmorillonite (Mmt) reveal that the interlayer spacing of the Mmt treated by the CR-PCE samples was lower than that of the Mmt treated by the C-PCE sample. It can thus be concluded that the functional monomer can effectively improve the clay tolerance performance of PCE.