Process for brominating butadiene polymers using mixed solvents

摘要

Butadiene polymers are brominated using a quaternary ammonium or quaternary phosphonium tribromide as the brominating agent. The bromination is performed in a solvent mixture than contains at least one polyhalogenated alkane and at least one monohalogenated alkane. The process proceeds easily under mild conditions and allows high conversions to be achieved easily.

主权项

1. A process for forming a brominated butadiene polymer comprising reacting a butadiene polymer containing aliphatic carbon-carbon double bonds with a quaternary ammonium tribromide or a quaternary phosphonium tribromide, in the presence of a solvent mixture containing at least one polyhalogenated compound selected from dichloromethane, dibromomethane, bromochloromethane, 1,2-dichloroethane, 1,1-dichloroethane, 1,2-dibromoethane 1,1-dibromoethane, or a mixture of two or more thereof, and at least one monohalogenated alkane, wherein the ratio of the polyhalogenated compound and the monohalogenated alkane is from about 3:1 to about 1:3 by weight, to form a solution of the brominated butadiene polymer in the solvent mixture and a quaternary ammonium monobromide salt or quaternary phosphonium monobromide salt as a by-product.