文档介绍：Materials Science and Engineering, A162 (1993) 257-264 257
"Inverse" organic-posite materials: high glass content
non-shrinking sol-posites
Bruce M. Novak and Mark W. Ellsworth
Department of Chemistry, Universityof California at Berkeley, Berkeley, CA 94720 (USA)
Abstract
We, as well as others, have been interested in the sol-gel process for the synthesis of hybrid posite
materials. Since our first report on the application of tetraalkoxysilanes possessing polymerizable alkoxides for the
production of non-shrinking sol-posites, we have extended our efforts towards increasing the glass content in
posite materials. The stoichiometry in the tetraalkoxysilanes limits the maximum glass content in the original
non-posites to 10%-18%. In order to increase the glass content to greater than 50%, we focused our efforts
on the use of silicic acid oligomers. Molecular weights of the poly(silicic acid) materials were varied from M~ = 5000 to
M, = 2 000 000 by controlling reaction conditions. In addition, branching ratios (. linear vs. spherical particles) can be
controlled by changing the catalysts used. The properties of the posite can range from a transparent flexible
material to a transparent hard material simply by changing anic polymer in posite.
1. Introduction als [5]. These glass posites have found a
variety of uses ranging from fibergl