SMOKE SUPPRESSION BY MIXED-METAL CU(II) OXIDES IN COMMERCIALLY FORMULATED FLEXIBLE PVC: A NEW SYNERGISTIC EFFECT

摘要

Meeting smoke standards is typically required in flexible PVC applications using flame retardants. Perhaps the most rigorous standard is NFPA 262, established by the National Fire Protection Association for plenum-rated communications cables. In order to meet this criterion, molybdate smoke suppressants are often introduced. In this work we demonstrate that in a commercial-type flexible PVC formulation, various mixed-metal oxides of Cu(II) are effective smoke suppressants when used alone and strongly synergistic for smoke suppression when they are combined. Particularly attractive for both smoke and flame suppression is a synergistic binary blend of Cu3(MoO4)2(OH)2 and CuTi3O7, which is much more active for smoke suppression than the well-known commercial additive, ammonium octamolybdate. Smoke performance was assessed according to ASTM-E662 and ASTM-E1354.