A microstructural analysis of isoprenol ether-based polycarboxylates and the impact of structural motifs on the dispersing effectiveness
- Technische Universität München, Chair for Construction Chemistry, 85747 Garching, Lichtenbergstraße 4 (Germany)
- Technische Universität München, Chair for Biochemistry, 85747 Garching, Lichtenbergstraße 4 (Germany)
- China Building Materials Academy, State Key Laboratory of Green Building Materials, 100024 Beijing (China)
- Beijing University of Technology, College of Materials Science and Engineering, 100124 Beijing (China)
Generally, polycarboxylate superplasticizers (PCEs) are synthesized via aqueous free radical copolymerization. The conditions during copolymerization such as relative reactivity and feeding mode and ratio of monomers can cause different monomer sequences in the final product. In this study, the sequence of monomers in PCE polymers synthesized from acrylic acid and isoprenyloxy polyethylene glycol (IPEG) macromonomer was characterized by {sup 13}C nuclear magnetic resonance (NMR) spectroscopy. Three different triads of monomer sequences (EAE, AAE and AAA; E = ether, A = acid monomer) were detected. It was found that IPEG PCEs predominantly contain the structural motifs of AAE and EAE, and less of AAA. Higher additions of acrylic acid do not incorporate into the structure of PCE, but convert to HMW polyacrylate as by-product instead. A PCE with optimal dispersing effectiveness was achieved at high contents of IPEG macromonomer, a molecular weight (M{sub w}) around 40,000 Da and narrow molecular weight distribution.
- OSTI ID:
- 22696559
- Journal Information:
- Cement and Concrete Research, Vol. 84; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
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