Synergistic action of Sb2O3 with bromine-containing flame retardant in polyolefins. 1—the variance in their performance versus Sb/Br ratio

✍ Scribed by Takashi Handa; Toshiaki Nagashima; Naobumi Ebihara

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 743 KB
• Volume: 3
• Category: Article
• ISSN: 0308-0501
• DOI: 10.1002/fam.810030202

✦ Synopsis

The synergistic action of antimony (Sb) with bromine (Br) was studied for polypropylene-2,3-dibromopropylpentabromophenyl ether-Sb203 systems at various Sb/Br molar ratios. Oxygen index, weight loss rate and heating value were used to evaluate the retardant effect. Bromine and antimony emission and their material balances were measured by gravimetric and X-ray fluorometric analysis of heated samples at each reaction time. Retarded HBr formation in the gaseous phase through SbBn was recognized by the presence of Sb203, matching the major emission of carbon fractions. Formation of SbBn, SbOBr and Sb4OaBrz was proved by X-ray diffraction analysis of heated residues and model products. SbBra and HBr formation were greatest at Sb/Br ratios of 1/3 and 1/4, respectively, while the highest oxygen index and the lowest weight loss rate and heating value were obtained at 1/4. Consequently, HBr will most probably produce the retardant effect rather than SbBr3. Effective synergistic action at the Sb/Br ratio of 1/4 is explained by presuming the formation of an acidic HBr-SbBrs complex in the molten phase for the particular reaction pattern of bromine in 2,3-dibromopropylpentabromophenyl ether.