Brominated flame retardant

1. A process for preparing a polybromoaryl ether comprising:

(A) adding to a solvent for the polybromoaryl ether a mixture of:

(1) at least one compound of the structure

HO—Ar—X 1 X 2 X 3 X 4 X 5   (I)

wherein Ar is an aryl group and X 1 X 2 X 3 X 4 and X 5 are independently selected from the group consisting of hydrogen and bromine, provided that at least one of X 1 X 2 X 3 X 4 and X 5 is bromine,

(2) at least one alkali or alkaline metal hydroxide, and

(3) at least one polymerization initiator,

wherein said solvent for the polybromoaryl ether is a non-solvent for alkali or alkaline metal bromides;

(B) mixing the materials prepared in (A) to polymerize compound I and form the polybromoaryl ether and at least one alkali or alkaline metal bromide by-product;

(C) quenching the polymerization of compound I; and then

(D) separating the insoluble alkali or alkaline metal bromide by-product using filtration from the soluble polybromoaryl ether.

2. The process of claim 1 wherein said solvent is tetrahydrofuran.

3. The process of claim 1 wherein:

said solvent is from about 100 wt % to 600 wt % tetrahydrofuran as based on compound I;

said alkali metal hydroxide is from about 100 mol % to 120 mol % sodium hydroxide as based on compound I; and

said polymerization initiator is from about 0.1 mol % to 30 mol % benzoyl peroxide as based on compound I.

4. The process of claim 1 wherein from 30.0 mol % to 0.5 mol % of benzoyl peroxide is reacted to result in said polybromoaryl ether having a molecular weight ranging from 4,000 to 62,000 Daltons.

5. The process of claim 1 wherein from 3.0 mol % to 1.0 mol % of benzoyl peroxide is reacted to result in said polybromoaryl ether having a molecular weight ranging from 15,000 to 40,000 Daltons.