Flame‐retardant blends of polyethylene‐octene elastomer (POE) and natural rubber (NR) filled with expandable graphite (EG) were melt‐mixed with azodicarbonamide to prepare elastomeric foams. The effect of the NR incorporation on the properties of EG filled POE foam was investigated. Gel content and microstructure observations revealed that the addition of NR into the POE/EG blend induced change in molecular structure, which produced a finer cellular structure during foaming. The compressive strength and elastomeric recovery of the POE/NR/EG blend foams were found to increase with increasing NR content. Based on the limiting oxygen index and horizontal burning measurements, all the POE/NR/EG blend foams were found to have good flame‐retardant properties. On the other hand, these POE/NR/EG blend foams exhibited higher combustion rates with an increasing NR content under high heat radiation and temperature in a cone calorimeter test. This study demonstrates that the combined use of NR as a modifier and EG as a flame retardant in POE foams provides an effective and practical method of obtaining well‐balanced improvements in cellular structure, mechanical properties, and flame resistance.

中文翻译：

---

天然橡胶和可膨胀石墨改性的聚乙烯辛烯泡沫的发泡和物理性能，阻燃性和可燃性

将填充有可膨胀石墨（EG）的聚乙烯-辛烯弹性体（POE）和天然橡胶（NR）的阻燃共混物与偶氮二甲酰胺熔融混合以制备弹性体泡沫。研究了NR掺入对EG填充的POE泡沫的性能的影响。凝胶含量和微观结构观察表明，在POE / EG共混物中添加NR会引起分子结构的变化，从而在发泡过程中产生更精细的孔结构。发现POE / NR / EG共混泡沫的压缩强度和弹性回复率随NR含量的增加而增加。根据极限氧指数和水平燃烧测量结果，发现所有POE / NR / EG共混泡沫均具有良好的阻燃性能。另一方面，在锥形量热仪测试中，这些POE / NR / EG共混泡沫在较高的热辐射和温度下表现出较高的燃烧速率，且NR含量增加。这项研究表明，在POE泡沫中，NR作为改性剂和EG作为阻燃剂的组合使用提供了一种有效且实用的方法，可在泡孔结构，机械性能和阻燃性方面取得良好平衡的改善。