Hyperbranched polyalkoxysiloxane: A unique silica precursor for the preparation of nanocomposites

POLY 336

Xiaomin Zhu, zhu@dwi.rwth-aachen.de1, Karin Peter1, Martin Moeller, moeller@dwi.rwth-aachen.de1, Claudiu Melian2, Alina Adams-Buda2, and Dan E. Demco2. (1) Deutsches Wollforschungsinstitut an der RWTH Aachen e.V, Pauwelsstrasse 8, D-52056 Aachen, Germany, (2) Institut für Technische und Makromolekulare Chemie, RWTH Aachen, Worringer Weg 1, D-52056 Aachen, Germany
A unique liquid precursor polymer of silicon dioxide – hyperbranced polyalkoxysiloxane (PAOS) was developed. It was prepared via a one-pot synthetic route from tetraethoxysilane with acetic anhydride in the presence of an organotitanium catalyst. Volatile fractions were completely removed on a thin-film evaporator. Based on this product an industrial compatible in situ sol-gel process for the preparation of polymer/silica nanocomposites was established. Solid state NMR spectroscopy showed that the in situ conversion of PAOS in PP proceeded to a large extent. With unmodified PAOS this procedure yielded PP/silica composites with coexistence of submicron- and nano-particles. PP/silica nanocomposite with particle diameter less than 100 nm was obtained using PAOS modified with long alkyl chains. TGA showed that PP/silica composites prepared using in situ sol-gel technology had improved thermal properties.
 

Silicones and Silicone-Modified Materials
8:30 AM-12:00 PM, Tuesday, 12 September 2006 San Francisco Marriott -- Salon A2, Oral

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006