Synthesis and characterization of a novel early-strength polycarboxylate superplasticizer and its performances in cementitious system

A novel early-strength type polycarboxylate superplasticizer (PCE) was synthesized by a new design of molecule structure such as introducing long polyoxyethlene side chains, functional monomer (2-acrylamide-2-methylpropanesulfonic acid), and optimizing monomer composition. In this study, with introducing the sulfonate groups into PCE structure, its dispersion capacity and the absorbed amount are increased firstly and then decreased, but the retardation hydration effect is weakened gradually. The molecular weight, adsorbed amount, and dispersion capacity of PCEs firstly increased and then decreased with increasing the AA/TPEG monomer molar ratio, and the same trend as the compressive strength harden concrete with PCEs at the age of 1, 3, and 28 days. The early-strength type PCE exhibits good dispersive capacity and weak retardation hydration effect in cementitious system, and the early age strength of concrete with addition of early-strength type PCE develops quickly. This study indicates that reasonable design of PCE molecule structure and synthesis method can obtain a novel early-strength type PCE which makes a good balance between workability and fast development of early age strength in cementitious system. (c) 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48906.