Patent ID: 8362153

Claim:
A process for preparing a polyisobutenyl sulfonate comprising: a. polymerizing isobutene in a quasi-living polymer system to form a quasi-living carbocationically terminated polymer comprising contacting an isobutene monomer with an initiator in the presence of a Lewis Acid selected from the group consisting of titanium tetrahalide, boron trichloride, aluminum trichloride, tin tetrachloride, zinc chloride, and ethyl aluminum dichloride, and a solvent, under suitable quasi-living polymerization reaction conditions to obtain a polymer having a number average molecular weight of about 350 to 5,000, and a ratio of weight average molecular weight to number average molecular weight M w /M n of less than about 1.4; b. contacting the polymer prepared in step a) with a suitable quenching agent whereby said quenching agent converts the quasi-living carbocationically terminated polymer to a polyisobutene polymer having at least 90 mole percent methyl-vinylidene content, wherein the suitable quenching agent is a dihydrocarbyl substituted nitrogen-containing five-membered aromatic compound selected from substituted pyrrole and substituted imidazole wherein the substituents are selected so that the substituted pyrrole or substituted imidazole is able to facilitate in preparing a vinylidene terminated polymer from a quasi-living carbocationically terminated polyisobutene; c. reacting the polyisobutene polymer of step b) with a sulfonating agent in a ratio of 0.9 to 1.2 and thereafter neutralizing with a source of alkali metal or alkaline earth metal.