Abstract: A process for the preparation of polybutene having an exo-olefin content of at least 50 mol. % from an isobutene-containing monomer feedstock, which process comprises contacting said isobutene-containing feedstock with a Lewis acid catalyst complexed with a Lewis base, in an apolar polymerization medium, and initiating polymerization of said isobutene-containing feedstock. The Lewis acid catalyst is of formula R?AlCl2, wherein R? is hydrocarbyl; the Lewis base is a dihydrocarbyl ether wherein each hydrocarbyl group is independently selected from C1-C8 hydrocarbyl groups and one or both hydrocarbyl groups of the dihydrocarbyl ether are substituted with an electron-withdrawing group; and the initiator is a compound of formula RX, wherein X is a halide; R is a hydrocarbyl group capable of forming a stable carbocation, and the carbon linking group R to group X is tertiary, benzylic, or allylic.

Abstract: A process for the preparation of polybutene having an exo-olefin content of at least 50 mol. % from an isobutene-containing monomer feedstock, which process comprises contacting said isobutene-containing feedstock with a Lewis acid catalyst complexed with a Lewis base, in an apolar polymerization medium, and initiating polymerization of said isobutene-containing feedstock. The Lewis acid catalyst is of formula R?AlCl2, wherein R? is hydrocarbyl; the Lewis base is a dihydrocarbyl ether wherein each hydrocarbyl group is independently selected from C1-C8 hydrocarbyl groups and one or both hydrocarbyl groups of the dihydrocarbyl ether are substituted with an electron-withdrawing group; and the initiator is a compound of formula RX, wherein X is a halide; R is a hydrocarbyl group capable of forming a stable carbocation, and the carbon linking group R to group X is tertiary, benzylic, or allylic.

Abstract: An improved process for the preparation of polybutene having an exo-olefin content of at least 50 mol. % by the polymerization of iso-butene, or a C4 feed containing iso-butene and other C4 olefins using (i) a Lewis acid.Lewis base catalyst complex and an alkyl halide initiator, in a substantially or completely apolar polymerization medium, in the presence of a hindered alcohol or alkoxyaluminum dichloride. In the above polymerization reaction, it has been found that a hindered alcohol or hindered alkoxyaluminum dichloride will function as an “exo enhancer” resulting in high isobutene conversion and the production of a polybutene product having a high terminal vinylidene content, while maintaining a target molecular weight.