Method for producing brominated and halohydrated polymers
AssigneeDow Global Technologies LLC
InventorsJohn W. Hull, JR., Shari Kram, Michal Elizabeth Porter, William G. Stobby
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Abstract
Conjugated diene polymers such as a styrene-butadiene copolymer are sequentially brominated by reaction with a quaternary ammonium tribromide or quaternary phosphonium tribromide and halohydrated by reaction with an N-haloimide compound. This produces a brominated and halohydrated polymer with very good thermal stability. The product is useful as a flame retardant in a variety of polymer systems.
Claims20
A process for preparing a brominated and halohydrated polymer of at least one conjugated diene, comprising (a) reacting a starting polymer of at least one conjugated diene with a quaternary ammonium tribromide, quaternary phosphonium tribromide compound or both a quaternary ammonium tribromide and a quaternary phosphonium tribromide to brominate 50% to 98% of the conjugated diene repeating units in the starting polymer to form a partially brominated polymer and then (b) reacting the partially brominated polymer with an N-haloimide compound in the presence of water and a water-miscible solvent system for the partially brominated polymer to halohydrate at least a portion of the remaining conjugated diene repeating units and produce a brominated and halohydrated polymer.
The process of wherein 65 to 95% of the conjugated diene units are brominated in step (a), 5 to 35% of the conjugated diene units are halohydrated in step (b), and 0 to 5% of the conjugated diene units are unreacted.
(canceled)
The process of any preceding claim wherein the brominated and halohydrated polymer is formed into particles.
A brominated and halohydrated polymer of at least one conjugated diene, wherein 2 to 50% of the conjugated diene units of the polymer are halohydrated, 50 to 98% of the conjugated diene units are brominated and 0 to 10% of the conjugated diene units are unreacted, which brominated and halohydrated polymer has a 5% weight loss temperature of at least 250° C.
15-20. (canceled)
Dependencies are inferred from the claim text.