Ignition properties of polymers evaluated from ignition temperature and ignition limiting oxygen index

Abstract

AbstractAn apparatus for measuring ignition temperature and ignition‐limiting oxygen index was devised in order to study ignition properties of polymers. Ignition limiting oxygen index, which was suggested by the limiting oxygen index (ASTM D2863‐70), was defined as the minimum volume fraction of oxygen required for ignition to occur in a slowly rising gaseous atmosphere. The ignition temperatures and the ignition limiting oxygen indexes of typical polymers were measured by this apparatus. Polymers which produced more ethylene by pyrolysis tend to have lower ignition temperatures. In the case of the same kinds of polymers, plots of ignition temperatures versus ignition limting oxygen indexes gave nearly straight lines (Fig. 3), but the straight line of depolymerization‐type polymers differed from that of random degradation‐type polymers differed from that of random degradation‐type polymers. In most polymers, ignition limiting oxygen indexes were nearly proportional to limiting oxygen indexes, but in the cases of hard poly(vinyl chloride) and soft poly(vinyl chloride), the plots did not follow this relation (Fig. 4). Ignition properties of self‐extinguishing polymers were also studied.