Hostname: page-component-76fb5796d-zzh7m Total loading time: 0 Render date: 2024-04-27T02:51:58.596Z Has data issue: false hasContentIssue false

Silylation of Partially Aggregated Colloidal Silica Nanoparticles for Reinforcement in Silicone Elastomers

Published online by Cambridge University Press:  10 February 2011

Timothy C. Chao
Affiliation:
Dow Corning Corporation, New Ventures R&D, Midland, MI 48686
Debora F. Bergstrom
Affiliation:
Dendritic Nanotechnologies Limited, Mount Pleasant, MI 48859
Get access

Abstract

Aqueous suspensions of colloidal silicas are readily silylated with chlorosilanes in the presence of acid and isopropyl alcohol without aggregation of the silica particles. By using chlorosilanes, spherical nanoparticles with controlled functionality can be made and transferred to an organic phase to provide stable, water free suspensions. The hydrophobic colloidal silica particles readily disperse into silicone polymers. In order to provide mechanical reinforcement comparable to traditional fumed silicas, a high filler loading of ca. 60 wt % mono-dispersed colloidal silicas need to be used.

Recently a unique pearl necklaced-shaped colloidal silicas become commercially available. These nanoparticles are successfully silylated and they maintain the original structures as evidenced by transmission electron microscopy (TEM). They are compounded into silicone polymers at ca. 30 wt % and they provide excellent viscosities and mechanical properties, especially the tear strengths. In this paper, we present the silylation, characterization and mechanical properties of these partially aggregated colloidal silica nanoparticles in silicone elastomers.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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

1. Stober, W., Fink, A. and Bohn, E., J. Colloid Interface Sci. 26, 62 (1968).Google Scholar
2. Vail, J. G., Soluble Silicates (ACS Monograph Series) Vol. 1 and 2, Reinhold, New York, 1961.Google Scholar
3. Kwan, K. S., Harrington, D. A., Moore, P. A., Hahn, J. R., Degroot, J. V. Jr, Burns, G. T., Rubber Chem. Tech., 71 (4), 630 (2001).Google Scholar
4. Badley, R. D., Ford, W. T., McEnroe, F. J. and Assink, R. A., Langmiur 6, 792 (1990).Google Scholar
5. Ketelson, H. A., Brook, M. A. and Pelton, R. H., Chem. Mater. 7, 1376 (1995).Google Scholar
6. Burns, G. T., Deng, Q., Field, R., Hahn, J. R. and Lentz, C. W., Chemistry of Materials 11, 1275 (1999).Google Scholar
7. Burns, G. T. et al., U.S. Patent No. 6051672 (Apr. 18, 2000).Google Scholar
8. Kraus, G. (ed.), Reinforcement of Elastomers, Interscience, New York, 1965.Google Scholar
9. Donnet, J. B. and Vidal, A., Adv. Polym. Sci., 76, 103 (1986).Google Scholar
10. Donnet, J. B., Rubber Chem. Tech.: Rubber Rev., 71 (3), 323 (1998).Google Scholar
11. Castaing, J. C., Allain, C., Auroy, P., Auvray, L., and Pouchelon, A., Europhys. Lett. 36, 2, 153 (1996).Google Scholar
12. Watanabe, Y. et al., U.S. Patent No. 5597512 (Jan. 28, 1997).Google Scholar
13. Watanabe, Y. et al., European Patent Application 1114794A1 (Nov. 7, 2001).Google Scholar
14. Yoshitake, K. et al., U.S. Patent No. 6025455 (Feb. 15, 2000).Google Scholar
15. Chao, T. C., unpublished results.Google Scholar