Grafting tertiary amine groups into the molecular structures of polycarboxylate superplasticizers lowers their clay sensitivity

A monomer containing a tertiary amine group was employed to synthesize polycarboxylate superplasticizers (PCEs) preparing from acrylic acid (AA), itaconic acid (IA) and 2-(dimethylamino) ethyl methacrylate (DMAM). The terpolymers were characterized and tested for their dispersion performance in the absence and presence of montmorillonite (Mmt). These novel PCEs displayed better dispersion performances in cement in the presence of Mmt than did conventional PCE. Adsorption measurements and X-ray diffraction analysis suggested that these novel PCEs interacted with Mmt only via surface adsorption, in contrast to the interaction of conventional PCE with Mmt by both surface adsorption and chemical intercalation.