EFFECT OF ZINC AND ZINC BORATE ON FIRE PROPERTIES OF MODIFIED POLYPHENYLENE OXIDE

Modified polyphenylene oxide resin (m-PPO) (virgin) and m-PPO flame re tarded with triaryl phosphate (FR m-PPO) were blended with zinc borate , zinc, and zinc/zinc borate. Both virgin and FR m-PPO containing zinc borate showed a marked reduction in smoke production (flaming and non -flaming-NBS Smoke Chamber). In FR m-PPO a reduction in oxygen index v alues was seen for zinc borate, except at the highest level tested (50 PHR). Zinc, on the other hand, showed an increase in oxygen index for FR m-PPO. Given the potential for both condensed and vapor phase acti vity for triaryl phosphate in m-PPO, the reduction in both smoke and o xygen index by zinc borate suggests a deactivation of the vapor phase activity of triaryl phosphate.