Synthesis and characterization of a PAMAM dendrimer-based superplasticizer and its effect on the properties in cementitious system

In this work, a polyamidoamine dendrimer-based polycarboxylic superplasticizer (DPC) with a crosslinked emanative structure was synthesized via simple free radical polymerization. H-1-nuclear magnetic resonance and Fourier transform infrared spectroscopy measurements were used for structural characterization. The fluidity, rheology behavior, and compressive strength of the cement/DPC samples were investigated in detail. The DPCs performed better dispersion and dispersion maintaining capabilities, stronger water reduction capability, and higher adsorption amounts than the conventional comb-shaped superplasticizer. The dispersive capacity of the DPC increased with an increasing generation of polyamidoamine dendrimers. Besides, compared with conventional comb-shaped superplasticizer, the addition of DPC led to a delayed and lowered heat flow peak on the hydration of cement paste at early age of hydration process. Furthermore, compressive strength results showed that the cement/DPC samples performed higher compressive strength than blank cement samples. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46550.