Abstract: Ammonium polyphosphate (APP) and pentaerythritol (PER) were introduced into EVA resin as an intumescent flame retardant (IFR). SiO2 and 4A zeolite have been used to improve the fire performance of the IFR-containing EVA. Limited oxygen index and thermal gravimetric analysis were used to characterize the flammability and thermal behavior of EVA composites. The morphology of the composite was observed and analyzed using SEM. It was found that a little amount of 4A zeolite could significantly improve the limited oxygen index value. The limited oxygen index of the sample containing 1 phr 4A zeolite reached 31%, contrasted to 29 % of the plain sample. When 3 phr silica was further added, the limited oxygen index increased to 32 % and V-0 level was reached in UL 94 test.

Key words: ethylene vinyl acetute copolymer, 4A zeolite, silica, flame retardancy