Abstract
The gelation of solutions containing mixtures of tetraethoxysilane (TEOS) and polydimethyl siloxane (PDMS) with isopropanol, H2O, and HCl as the catalyst was studied at various temperatures in closed systems. Large variations in the gelation rates were observed with varying temperatures, and different acid and water contents. The gelation rates were found to increase with increasing temperature as well as with HCl, content. However, decreasing the water concentration (the molar ratio H2O∶TEOS<3) had a more significant effect in decreasing the gelation rate. Apparent activation energies were obtained from Arrhenius plots of gelation time against temperature and they were shown to change with acid content. The microstructural evolution in the final, dried gels appeared to be related to the degree of network linkage in the present system.
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References
G. Philipp and H. Schmidt, J. Non-Cryst. Solids 63 (1984) 283.
H. Schmidt, ibid. 73 (1985) 681.
G. L. Wilkes, B. Orler and H. Huang, Polym. Prepr. 26 (1985) 300.
Y. Charbouillot, D. Ravaine, M. Armand and C. Poinsignon, J. Non-Cryst. Solids 103 (1988) 325.
H. Huang, B. Orler and G. L. Wilkes, Macromolecules 26 (1987) 1322.
Y. Hu and J. D. Mackenzie, to be published in J. Mater. Sci. (1992).
Y. J. Chung, S. Ting and J. D. Mackenzie, Mater. Res. Soc. Proc. 180 (1990) 981.
C. J. Brinker, K. D. Keefer and D. W. Schaefer, J. Non-Cryst. Solids 48 (1982) 47.
K. Kamiya, Y. Iwamoto, T. Yoko and S. Sakka ibid. 100 (1988) 195.
R. Aelion, A. Loebel and F. Eirich, J. Amer. Chem. Soc. 72 (1950) 5705.
K. C. Chen, T. Tsuchiya and J. D. Mackenzie, J. Non-Cryst. Solids 81 (1986) 227.
R. Anderson, B. Arkles and C. L. Larson, “Petrarch systems silanes and silicones” (Petrarch Systems, New York, 1987).
E. J. A. Pope and J. D. Mackenzie, J. Non-Cryst. Solids 87 (1986) 185.
M. W. Colby, A. Osaka and J. D. Mackenzie, ibid. 82 (1986) 37.
Idem., ibid. 99 (1988) 129.
R. H. Harding, ASTM STP414 (American Society for the Testing of Materials, New York, 1967) 3.
C. B. Hurd and R. W. Barclay, J. Phys. Chem. 44 (1940) 847.
M. F. Bechtold, W. Mahler and R. A. Schunn, J. Amer. Chem. Soc. 90 (1968) 4590.
M. F. Bechtold, R. D. Vest and L. Plambeck, Jr, J, Polym. Sci. Polym. Chem. Ed. 18 (1980) 2823.
S. P. Moulik and B. N. Gosh, J. Ind. Chem. Soc. 40 (1963) 907.
V. Gottardi, M. Guglielmi, A. Bertoluzza, C. Fagnano, and M. A. Morelli, J. Non-Cryst. Solids 63 (1984) 71.
M. F. Bechtold, W. Mahler and R. A. Schunn, J. Polym. Sci.: Polym. Chem. Ed. 18 (1980) 2823.
C. B. Hurd, Chem. Rev. 22 (1938) 403.
J. D. Mackenzie, in “Science of ceramic chemical proceeding”, edited by L. L. Hench and D. R. Ulrich (Wiley, New York, 1986) 113.
E. R. Pohl and F. D. Osterholtz, in “Molecular characterization of composite interfaces”, edited by H. Ishida and G. Kumar (Plenum, New York, 1985) 157.
Y. J. Chung, PhD. thesis, University of California, Los Angeles, 1991.
K. W. Suh and R. E. Skochdopole, in “Encyclopedia of chemical technology”, Vol. 3 edited by N. M. Bikales (Wiley, New York, 1980) p, 80.
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Hu, Y., Chung, Y.J. & Mackenzie, J.D. Gelation kinetics of an organically modified silicate. JOURNAL OF MATERIALS SCIENCE 28, 6549–6554 (1993). https://doi.org/10.1007/BF00356392
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DOI: https://doi.org/10.1007/BF00356392