| Autor: |
Moriya, Osamu, Yamamoto, Shin-ichi, Sugizaki, Toshio, Maeda, Jun, Kamejima, Atsuko, Kumon, Takeo, Kageyama, Toshifumi |
| Předmět: |
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| Zdroj: |
Polymer Journal; 2005, Vol. 37 Issue 4, p262-269, 8p, 2 Diagrams, 4 Charts, 5 Graphs |
| Abstrakt: |
The gels of the rare earth metal silicate such as yttrium, neodymium, or samarium were found to be the effective solid catalysts for the ring opening polymerization of oxetane. The silicate gels were prepared by the co-gelation of sodium metasilicate and the rare metal chloride from an acidic aqueous solution through the neutralization by an aqueous ammonia, the surface areas of which were in the range from 142 to 213 m² g-1. The ring opening polymerization of oxetane proceeded readily at 20 °C in the presence of a catalytic amount of the silicate gels, in which the content of the rare earth metal was 10 mol % to oxetane. The silicate gel of yttrium, which enabled the quantitative formation of the corresponding polymer, was the most effective solid acid among those of the rare earth metals employed in this work. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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