Synthesis and performance of methacrylic ester based polycarboxylate superplasticizers possessing hydroxy terminated poly(ethylene glycol) side chains

The synthesis and performance of new methacrylate ester based polycarboxylate superplasticizers is shown. These new superplasticizers possess hydroxy termination of the poly(ethylene glycol) side chains instead of conventional methoxy termination. Properties of the new superplasticizers in cement paste were compared to those of conventional ones. For this comparison, methacrylic acid-poly(ethylene glycol) methacrylate ester copolymers having three different side chain lengths and either hydroxyl or methoxy terminated graft chains were synthesized. For characterization of the superplasticizers, gel permeation chromatography (GPC) as well as anionic charge density determination was carried out. The performance of the polymers in cement was tested by measuring paste flow, adsorption as well as zeta potential. Additionally, retardation of the copolymers possessing side chains of 45 ethylene oxide units was investigated by heat calorimetry. According to the data, macromonomers based on hydroxy terminated poly(ethylene glycol) methacrylate ester chemistry allow to produce superplasticizers of high quality. (C) 2008 Elsevier Ltd. All rights reserved.