Patent ID: 8901031

Claim:
A composition formed by a process comprising the steps of: (a) combining poly(2,6-diphenyl-1,4-phenylene oxide) and a mineral acid in a reaction vessel; (b) adding a source of bromine to the reaction vessel to create a reaction mixture; (c) purging the reaction mixture with an inert gas to remove HBr released from the reaction mixture until the reaction is complete; (d) adding an alcohol to precipitate the formed tri-brominated poly(2,6-diphenyl-1,4-phenylene oxide) within the mixture; and (e) filtering the mixture to obtain tri-brominated poly(2,6-diphenyl-1,4-phenylene oxide), wherein said composition comprise polymers of tri-brominated poly(2,6-diphenyl-1,4-phenylene oxide) having a constitutional unit denoted by the general formula shown below, wherein said composition has a glass transition temperature of 275° C., a CO 2 permeability of 90.2 Barrer, a N 2 permeability of 3.2 Barrer and CO 2 / N 2 permselectivity of 29.3