| 摘要 |
<p>The invention concerns a composition based on a grafted metal oxide, its preparation and its use in a polymerisation method by opening oxygenated cycles such as alkyl oxides, cyclic esters or cyclic carbonates. Said composition comprises a support selected in the group of metal oxides capable of having hydroxyl functions, whereon is grafted a group of formula (1): M(OR)n in which M is an element selected among scandium, zirconium, hafnium, niobium, tantalum, rare earths and actinides; R is an organic group and n is whole number not less than 1. The composition is prepared by forming a suspension of said support, then contacting and reacting said suspension with a compound of formula (2): M(OR)n+1 in which M, R and n are defined as above.</p> |
