Bis[(4 -b-(2-bromopropanoate)ethoxy)phenyl]phenylphosphine oxide was used for the first time as the initiator of atom transfer radical polymerization of styrene and methyl methacrylate in the presence of CuBr/N, N,N 0 , N 00 , N 00 -pentamethyldiethylenetriamine as catalyst/ligand and dimethyl sulfoxide as solvent. The presence of phosphine oxide linkages in the backbone gives the polymers special properties; low T g, high char yield, and decreases the oxygen induction time value. A linear increase of number average molecular weight (M n ) versus monomer conversion was observed, and the molecular weight distribution was relatively narrow (M w /M n ¼ 1.1-1.3). FTIR, 1 HNMR, gel permeation chromatography, ultraviolet spectroscopies were used for the characterization of the related polymers. The thermal properties of these polymers were investigated by differential scanning calorimetry and thermogravimetric analysis.