Smoke Suppression and Fire Retardance of Poly(vinyl chloride) by Metal-Based Additives:Progress and Prognosis

摘要

Metal-based smoke suppressants and fire retardants for poly(vinyl chloride) (PVC) have beenstudied in this laboratory for several years. Additives containing copper have been of special interest inthis context, because they are able to cause crosslinking of the polymer without promoting charcracking. The principal crosslinking agent is thought to be Cu(0) formed in situ, and the crosslinkingmechanism has been shown to involve reductive coupling instead of Lewis-acid-promoted reactions.Cone calorimetry studies have now identified several copper additives that are highly effective as smokesuppressants and fire retardants for both rigid and plasticized PVC. Mixed-metal oxides of copper areespecially attractive in this regard, and some of them are strongly synergistic for smoke suppressionwhen they are combined. The current status of our research in this general area is described.