Two-step process for brominating butadiene copolymers
AssigneeDow Global Technologies LLC
InventorsJohn W. Hull, Jr., Douglas C. Greminger, Timothy J. Adaway
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Abstract
Butadiene copolymers are brominated using certain quaternary ammonium tribromides as the brominating agent in a first step, and then with elemental bromine in a second bromination step. The bromination process proceeds easily under mild conditions, and produces a brominated product that has excellent thermal stability. The bromination proceeds to high conversions in shorter reaction times, when the bromination is performed using only the first bromination step.
Claims11
A process comprising reacting in a first step a butadiene polymer containing unsaturated butadiene repeating units with a phenyltrialkylammonium tribromide, benzyltrialkylammonium tribromide or tetraalkylammonium tribromide in the presence of at least one solvent for the butadiene polymer, to form a partially brominated butadiene polymer in which from about 50 to about 96% of the butadiene repeating units are brominated, and then further reacting the partially brominated butadiene polymer in a second step with elemental bromine until greater than 96% of the butadiene repeating units have been brominated.
Dependencies are inferred from the claim text.