Synthesis and properties of methacrylate-based and allylether-based polycarboxylate superplasticizer in cementitious system

Abstract

Methacrylate-based as well as allylether-based polycarboxylate superplasticizers (PCs) were prepared and evaluated in this paper. The architectures of PCs were characterized by Fourier transform infrared spectroscopy and Nuclear magnetic resonance as well as Gel permeation chromatography. For evaluation the performance of PCs, the adsorption behavior, zeta potential, and their relation to the fluidity of cement paste have been investigated, respectively. Additionally, retardation of PCs was tested by a heat calorimeter. The results showed that allyether-based PCs have a better slump retention ability, particularly their fluidity loss is smaller than that of the methacrylate-based PCs. Both types of PCs can delay the initial hydration of cement, which can be attributed to their different molecular structures and can be elucidated based on the results of the adsorption behavior and zeta potential of the cement particles. This investigation will provide useful information for choosing or designing the proper PCs to produce workable concrete.