Anti-agglomerants for polyisobutylene production

A process for preparing a polyisobutene, the process comprising

• conducting a polymerization in a reaction medium comprising an organic diluent and at least one polymerizable monomer in the presence of an initiator system or catalyst to form an organic medium comprising an elastomer, the organic diluent and optionally residual monomers, wherein the elastomer forms a suspension of primary particles;
• and
• contacting said suspension of primary particles with an aqueous medium comprising at least one LCST compound having a cloud point of 0 to 100° C. determined by at least one of the following methods:
• DIN EN 1890 of September 2006, method A,
• DIN EN 1890 of September 2006, method C,
• DIN EN 1890 of September 2006, method E,
• DIN EN 1890 of September 2006, method A wherein the amount of compound tested is reduced from 1 g per 100 ml of distilled water to 0.05 g per 100 ml of distilled water, and
• DIN EN 1890 of September 2006, method A wherein the amount of compound tested is reduced from 1 g per 100 ml of distilled water to 0.2 g per 100 ml of distilled water
• thereby forming an aqueous slurry of elastomer particles,
• wherein
• the primary particles obtained during the polymerization agglomerate to form secondary particles, and
• the polymerizable monomer includes an isoolefin monomer having from 4 to 16 carbon atoms.