Synthesis of calcium silicate hydrate/polymer complexes: Part II. Cationic polymers and complex formation with different
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Synthesis of calcium silicate hydrate/polymer complexes: Part II. Cationic polymers and complex formation with different polymers Hiroyoshi Matsuyamaa) and J. Francis Young Center for Advanced Cement-Based Materials University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (Received 19 October 1998; accepted 20 May 1999)
Some high molecular weight cationic polymers, poly(diallyldimethylammonium chloride) (PDC) and poly(4-vinylbenzyltrimethylammonium chloride) (PVC), have been incorporated into the calcium silicate hydrate (C–S–H) structure during precipitation of quasicrystalline C–S–H from aqueous solution. Expansion of the interlayer spacing [0.9 nm (PDC), 1.5 nm (PVC)] and a high-carbon content provided evidence that these polymers were intercalated between layers of C–S–H when Ca/Si 13).6 Therefore, only quaternary ammonium derivatives were chosen, because they can keep the positive charge under this condition. B. Ion exchange of the polymer
Ion exchange of the counter anion in the polymers was performed by using ion exchange resin (DOWEX 1 × 8– 1000, Aldrich Chemical Co., Inc., Milwaukee, WI). The chloride ion in the resin was exchanged with hydroxide ion by flowing NaOH solution into the column; complete exchange to hydroxide ion was confirmed by the absence of an AgCl precipitate when Ag(NO)3 solution was added to the elute. The counter anion in the polymers, © 1999 Materials Research Society
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H. Matsuyama et al.: Synthesis of calcium silicate hydrate/polymer complexes: Part II
TABLE I. Cationic polymers. Cationics Abbreviation
MW
Carbon contenta
Poly(diallyldimethylammonium chloride) PDC 100,000–200,000
59.4
Poly(4-vinylbenzyltrimethylammonium chloride) PVC 150,000–200,000
68.7
Chemical structure
Poly(4-vinyl-1-methylpyridinium bromide) PMB 50,000 48.0
Poly(2-methacryloxyethyltrimethylammonium chloride) PTC 200,000
42.9
Hexadimethrine bromide HMB 5,000–10,000
70.1
Methyl glycol chitosan (iodide) MGI
B. Effect of polymer types
38.7
a
Mass% of carbon in monomer unit.
such as chloride and bromide ion, was then exchanged with hydroxide ion by passage through the column. The exchange to hydroxide ion from chloride or bromide ion was also confirmed by using Ag(NO)3 solution. Then, the hydroxide ion was replaced by bromide or chloride ion by titration using hydrochloric acid or hydrobromic acid solution (1 M). C. Analysis and equipment
The x-ray diffraction (XRD) 29Si and 13C solid-state nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared spectroscopy (FTIR) spectroscopy were used to characterize the complexes. Details of the procedures are given in Part I. III. RESULTS A. Effect of polymer concentration in solution
Figure 1 shows the XRD patterns of quasicrystalline C–S–H precipitated at an initial Ca/Si ratio of 0.8 in the presence varying concentrations of poly(diallyldimethyl3390
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ammonium chloride) (PDC), expressed as gram polymer per gram of s
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