In this work, a phosphorous-containing flame retardant, phenylphosphonate-based compound (EHPP), is synthesized by alcoholysis and hydrazinolysis of phenylphosphonic dichloride, which is subsequently introduced to ethylene-vinyl-acetate (EVA) copolymer to improve its flame retardant performance. The resultant compound was characterized by Fourier transform infrared (FTIR), 1 H NMR, 13 C NMR, and 31 P NMR. The influence of the EHPP on the combustion behaviors of EVA is studied by limiting oxygen index (LOI), UL-94, and cone calorimeter test. The results show that 1 wt% EHPP can reduce peak heat release rate (PHRR) by 40%. Moreover, 2 wt% EHPP can increase LOI from 20.5% to 25.5%. Thermogravimetric analysis/infrared spectrometry (TGA-FTIR) was used to detect the gaseous products of EVA/EHPP to study the gaseous-phase flame retardant mechanism. The EHPP released phosphorus-containing radicals to capture highly active free radicals to improve the flame retardancy of EVA.

中文翻译：

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降低乙烯-乙酸乙烯酯共聚物可燃性的氧化膦

在这项工作中，通过对二氯苯基膦酰氯进行醇解和肼解，合成了一种含磷的阻燃剂，基于苯基膦酸酯的化合物（EHPP），随后将其引入到乙烯-乙酸乙烯酯（EVA）共聚物中以提高其阻燃性能。通过傅立叶变换红外（FTIR），1 H NMR，13 C NMR和31 P NMR对所得化合物进行表征。通过极限氧指数（LOI），UL-94和锥形量热仪试验研究了EHPP对EVA燃烧性能的影响。结果表明，1 wt％的EHPP可以将峰值放热率（PHRR）降低40％。此外，2 wt％的EHPP可以将LOI从20.5％提高到25.5％。用热重分析/红外光谱法（TGA-FTIR）检测EVA / EHPP的气态产物，研究气相阻燃机理。