Study on the Flame Resistances of the Two Bromine Flame Retardants to Polyethylene XIONG Chuan-xi1, ZHANG Yi1, ZHOU Zhi-yong1,MIAO Zhan2,LI Xue2 (1.School of Materials Science and Engineering, Wuhan University of Technology,Wuhan 430070,China; 2.Yunnan Building Materials Scientific Research Designing Institute, Kunming 650221,China)The flame resistances and tensile strengths of decabromodiphenyl oxide (DBDPO) and octabromodiphenyl oxide (OBDPO), to low density polyethylene (LDPE) were researched. The difference in the behaviors of decompositon of DBDPO and OBDPO was compared by differential scanning calorimetry (DSC) and thermogravimetry (TG). Tests on the tensile strength of samples showed that OBDPO had little effect on the tensile strength of LDPE, while DBDPO had a great effect on the decrease of material. Measurements on the limiting oxygen index (LOI) indicated that Sb_2O_3 increased greatly the flame resistance of bromine flame retardant by its synergistic action; the flame resistance of DBDPO to LDPE was better than that of OBDPO; the optimum DBDPO content was about 12%, and the optimum ratio of DBDPO to Sb_2O_3 was 3; however, the optimum OBDPO content was about 16%, and the optimum ratio of OBDPO to Sb_2O_3 was 2.5.decabromodiphenyl oxide; octabromodiphenyl oxide; flame retardant; low density polyethylene