Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-29T09:23:26.509Z Has data issue: false hasContentIssue false
  • English
  • Français

Ormosils of High Hardness

Published online by Cambridge University Press:  21 February 2011

Takashi Iwamoto  and
John D. Mackenzie
Takashi Iwamoto
Affiliation:
University of California, Los Angeles, Department of Materials Science and Engineering, 405 Hilgard Ave., Los Angeles, CA 90024
John D. Mackenzie
Affiliation:
University of California, Los Angeles, Department of Materials Science and Engineering, 405 Hilgard Ave., Los Angeles, CA 90024
Get access

Abstract

Organically modified silicates (ormosils) of high hardness were prepared by the reactions of tetraethoxysilane (TEOS) and polydimethylsiloxane (PDMS) aided by ultrasonic irradiation. The mechanisms leading to the hard ormosil formation were investigated by liquid state 29Si NMR spectroscopy. PDMS chains were found to be broken into shorter chains and/or 4-membered siloxane rings during the reaction and finally, all PDMS chains were chemically incorporated as short chains into silica networks. Vickers hardnesses of the hard ormosils were measured and compared with those of the hardest transparent plastics. Whereas the hardest transparent plastics have Vickers hardness values of less than 25 kg/mm2, the hard ormosils have Vickers hardnesses up to higher than 150 kg/mm2. A theoretical model was developed for the calculation of Vickers hardnesses of the hard ormosils and agreed well with experimental results. Predictions based on this theory indicate that even harder ormosils can be made when Al2O3, ZrO2 and TiO2 are substituted for SiO2. Results based on these new ormosils are also presented.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 346: Symposium N – Better Ceramics Through Chemistry VI , 1994 , 397
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Philipp, G. and Schmidt, H., J. Non-Cryst. Solids 63, (1984) 283.Google Scholar
2 Wilkes, G.L., Orler, B. and Huang, H., Polym. Prepr. 26, (1985) 300.Google Scholar
3 Chung, Y.J., Ting, S.J. and Mackenzie, J.D., in Better Ceramics Through Chemistry IV. edited by Zelinski, B J.J., Brinker, C.J., Clark, D.E. and Ulrich, D.R. (Elsevier Science Publishers, New York, 1990), p. 981.Google Scholar
4 Hu, Y. and Mackenzie, J.D., in Better Ceramics Through Chemistry V. edited by Hampden-Smith, M.J., Klemperer, W.G. and Brinker, C.J., (Elsevier Science Publishers, New York, 1992), p. 681.Google Scholar
5 Hu, Y. and Mackenzie, J.D., J. Mater. Sei. 27, (1992) 4415.Google Scholar
6 Mackenzie, J.D., Chung, Y.J. and Hu, Y., J. Non-Cryst. Solids 147&148, (1992) 271.Google Scholar
7 Iwamoto, T., Monta, K. and Mackenzie, J.D., J. Non-Cryst. Solids 159, (1993) 65.Google Scholar
8 Hu, Y. and Mackenzie, J.D., J. Mater. Set., in press.Google Scholar
9 Monta, K., Hu, Y. and Mackenzie, J.D., in Better Ceramics Through Chemistry V. edited by Hampden-Smith, M.J., Klemperer, W.G. and Brinker, CJ., (Elsevier, New York, 1992), p. 693.Google Scholar
10 Morita, K., Hu, Y. and Mackenzie, J.D., J. Sol-Gel Science and Technology, in press.Google Scholar
11 Levy, G.C. and Cargioli, J.D., in Nuclear Magnetic Resonance Spectroscopy of Nuclei Other Than Protons, edited by Axenrod, T. and Webb, G.A. (Wiley, New York, 1974), ch. 17.Google Scholar
12 Yamane, M. and Mackenzie, J.D., J. Non-Cryst. Solids 15, (1974) 153.Google Scholar
13 Makishima, A. and Mackenzie, J.D., J. Non-Cryst. Solids 17, (1975) 147.Google Scholar
14 Makishima, A. and Mackenzie, J.D., J. Non-Cryst. Solids 12, (1973) 35.Google Scholar
15 Marsmann, H., in NMR-17. Oxygen-17 and Silicon-29. edited by Diehl, P., Fluck, E and Kosfeld, R. (Springer, Berlin, 1981), p. 65.Google Scholar
16 Imaoka, M., Hasegawa, H., Hamaguchi, Y. and Kurotaki, Y., Yogyo Kyokaishi 79, (1971) 164.Google Scholar
17 Ainworth, L., J. Soc. Glass Tech. 38, (1954) 501.Google Scholar
18 Sun, K.H., J. Amer. Ceram. Soc. 30, (1974) 277.Google Scholar