Flammability of EVA/IFR (APP/PER/ZB system) and EVA/IFR/synergist (CaCO₃, NG, and EG) composites

Abstract

Poly(ethylene-co-vinyl acetate)/intumescent flame retardant (ammonium polyphosphate/pentaerythritol/zinc borate system) composites-EVA/IFR (APP/PER/ ZB system) and EVA/IFR/Synergist [CaCO 3 , natural graphite, or expanded graphite (EG)] composites have been prepared by melting compounding method. The flammability, the combustion process, the quantity of the residual chars, the morphology of the residual chars, and the thermal stability of the chars have been investigated by cone calorimeter, scanning electron microscopy and thermo gravimetric analysis. The results indicate that heat release rate (HRR), total heat released, and total smoke release (TSR) of EVA/IFR (IFR 30 phr) composite decrease to about 67.1, 78.2, and 64% of that of pure EVA, respectively. HRR, THR, and TSR of EVA/IFR/EG (IFR 9 phr, EG 1phr) composite decrease to about 62.1, 76.2, and 44% of that of pure EVA, respectively. The quantity, the thermal stability of residual chars and the char structure are discussed to find the reasons of the phenomenon above. It has been found that the flame retardant of EVA vulcanizates is improved and the fire jeopardizing is dramatically reduced due to the addition of IFR and synergist, which can give some advice to design formulations for practical applications as cable.

Synergistic effects of ammonium polyphosphate and red phosphorus with expandable graphite on flammability and thermal properties of HDPE/EVA blends

“…However, the charred residues of samples (2), (4), and (9) after degradation are kept by 18.8, 12.3, and 10.8 wt% at the high temperature of 700°C, respectively. The possible reason is that EG expands and generates voluminous insulative layers to protect the underlying polymeric matrix when exposed to heat . The result is in agreement with CCT.…”

“…The charred residues of sample (1) is only 5.1%; however, the charred residues of samples (2), (4), and (9) are about 28.7%, 34.5%, and 38.1% after flammability, respectively. This is attributed to char formation and its morphological structure on the surface of the polymer matrix, and the favorable flame‐retardant synergistic effect of APP + RPM with EG . During the combustion, the compact charred residues may occur on the surface of the burning materials creating a physical protective barrier.…”

“…The flammability behavior of poly(ethylene‐co‐vinyl acetate) (EVA)/IFRs [ammonium polyphosphate/pentaerythritol/zinc borate (APP/PER/ZB) system] and EVA/IFRs/synergist (CaCO 3 , natural graphite, or EG) composites was investigated by Wu and his co‐authors . The results showed that the heat release rate (HRR), total heat release (THR), and total smoke release of EVA/IFRs/EG composites decreased to about 62.1%, 76.2%, and 44% compared with that of pure EVA, respectively.…”

Effect of the particle size of expandable graphite on the thermal stability, flammability, and mechanical properties of high-density polyethylene/ethylene vinyl-acetate/expandable graphite composites

“…The data from Table summarize that FPI of HDPE/EVA was 0.0044; however, FPI of HDPE/EVA/EG1 and HDPE/EVA/EG2 increased to 0.6371 and 0.4435, which were about 145 and 101 times of that of HDPE/EVA, respectively. Generally, the higher FPI and lower PHRR, the better is the fire resistance to reduce the loss and casualty in a real fire . This indicated that the flame‐retardant properties of HDPE/EVA/EG were improved greatly by the addition of EG.…”

“…Fire performance index (FPI), the ratio of TTI and PHRR, is generally used to design the escape time for firefighters in a real fire . The data from Table summarize that FPI of HDPE/EVA was 0.0044; however, FPI of HDPE/EVA/EG1 and HDPE/EVA/EG2 increased to 0.6371 and 0.4435, which were about 145 and 101 times of that of HDPE/EVA, respectively.…”