Process for preparing a halogenated elastomer with improved Mooney viscosity stability

A method of preparing a brominated elastomer, the method comprising:

• (a) polymerizing a C4 to C7 isomonoolefin and at least one monomer or other polymerizable unit to obtain a C4 to C7 isomonoolefin derived elastomer;
• (b) adding a first portion of a Mooney stabilizer to the C4 to C7 isomonoolefin derived elastomer;
• (c) contacting the C4 to C7 isomonoolefin derived elastomer with a halogenating agent and an emulsion in a bromination unit to form a brominated elastomer effluent, wherein an optional portion of the Mooney stabilizer is added to the bromination unit, wherein the emulsion comprises an oxidizing agent, water, solvent, and surfactant;
• (d) adding a portion of the Mooney stabilizer to the brominated elastomer effluent;
• (e) neutralizing the brominated elastomer effluent with a neutralizing agent and water to form a neutralized effluent, wherein an optional portion of the Mooney stabilizer is added to the neutralized effluent;
• (f) volatizing a hydrocarbon solvent from the neutralizing effluent to form a brominated elastomer slurry;
• (g) recovering a brominated elastomer from the brominated elastomer slurry, wherein an optional portion of the Mooney stabilizer is added to the recovered brominated elastomer.