| 主权项 |
1. A process for the preparation of polybutene having an exo-olefin content of at least 50 mol. %, which process comprises contacting isobutene or an isobutene-containing monomer mixture, with a Lewis acid catalyst complexed with an oxygen and/or sulfur-containing Lewis base, in a substantially or completely apolar solvent, and initiating polymerization of said isobutene or an isobutene-containing monomer mixture with an initiator, wherein said Lewis acid catalyst is a Lewis acid of the formula MR″mYn, wherein M is a metal selected from Al, Fe, Ga, Hf, Zr and W; R″ is a hydrocarbyl group; Y is halogen; m is 0 or an integer of 1 to 5; and n is an integer of 1 to 6, with the proviso that m+n is equal to the valency of metal M; said Lewis base is dihydrocarbyl ether, wherein each ether hydrocarbyl group is independently selected from C1 to C8 hydrocarbyl, wherein one or each of said ether hydrocarbyl groups are substituted with an electron-withdrawing group; the initiator is a compound of the formula RX, wherein X is a halide; R is a hydrocarbyl group capable of forming a stable carbocation, and wherein the carbon linking group R to group X is tertiary, benzylic or allylic. |
