Fire retardancy of polyethylene-alumina trihydrate containing clay as a synergist

The fire behavior of polyethylene combined with alumina trihydrate (ATH) and an oligornerically-modified clay has been studied. The combination of polyethylene with 2.5% inorganic clay and 20% ATH gives a 73% reduction in the peak heat release rate (PHRR), which is the same as that obtained when 40% ATH is used alone. A further increase in the clay loading does not improve the fire properties. Mechanical properties, such as elongation at break, can be improved in comparing compounds with or without clay at the same reduction in PHRR. The oligomerically-modified clay can also facilitate the melt blending process. Copyright (c) 2005 John Wiley & Sons, Ltd.