Rubbers with tunable levels of metal containing anti-agglomerants

A process for the preparation of an aqueous slurry comprising a plurality of copolymer particles suspended therein, the process comprising:

• contacting monomers comprising at least one isoolefin monomer and at least one multiolefin monomer in an organic diluent with an initiator system to polymerize the monomers to form copolymers in a medium comprising the copolymers, the organic diluent and optionally residual monomers;
• contacting the copolymer medium with an aqueous medium comprising at least one lower critical solution temperature compound having a cloud point of 0 to 100° C.;
• and
• removing at least partially the organic diluent and to the extent present in the medium removing at least partially the residual monomers to obtain an aqueous slurry comprising copolymer particles.