| 摘要 |
The invention relates to a composition based on a grafted metal oxide, its preparation and its use in a process of polymerization by opening oxygenated rings such as alkyl oxides, cyclic esters or cyclic carbonates. The composition comprises a support chosen from the group of metal oxides capable of containing hydroxyl functions, onto which is grafted a group of formula (1) -M(OR)n in which M is an element chosen from scandium, zirconium, hafnium, niobium, tantalum, rare-earth metals and actinides, R is an organic group and n is an integer greater than or equal to 1. The composition is prepared by forming a suspension of the abovementioned support and then placing in contact and reacting this suspension with a compound of formula (2) M(OR)n+1 in which M, R and n are defined as above. |
