Synthesis and Performance of Polycarboxylic Acid Superplasticizer with Crosslinked Linkage

Abstract

A new type of polycarboxylic acid superplasticizer (G18-PCEs) containing crosslinked linkage was synthesized by the method of the first esterification and then polymerization. Its monomer and polymer structure were confirmed by 1H nuclear magnetic resonance (NMR) spectroscopy and High-performance liquid chromatography. A series of G18-PCE polycarboxylic acid superplasticizers with different cross-linking degrees and segment structures were constructed and obtained. Compared with conventional comb-shaped superplasticizers (comb-PCEs), the cement suspension with G18-PCEs was observed to perform more excellent fluidity, lower slump loss, and lower degree of hydration at early ages. Furthermore, the adsorption behavior and solution performance of two kinds of superplasticizers were investigated, in which G18-PCEs show higher adsorption capacity (0.8mg/g) and air-entraining ability. In this work, we found that changing the topological structure of polycarboxylic acid superplasticizers from comb shape to moderately cross-linked type can optimize the dispersion effect, which provides a reference for the development of higher performance concrete superplasticizers.

Keywords: crosslinked linkage, Superplasticizer, esterification, air-entraining, Hydration