The suppression effects of Ammonium Polyphosphate (APP) with different mass fractions on the maximum explosion pressure (P_max), the explosibility index (K_st), the minimum ignition energy (MIE) and the minimum ignition temperature (MIT) of unsaturated polyester resin (UPR) dust were studied. Results indicated that the explosion severity and the ignition sensitivity of UPR dust decreased gradually when the mass fractions of APP increased. There existed a minimum inerting concentration (MIC), and the explosion of UPR dust could be suppressed completely by 60 wt% APP. Moreover, APP had a great inhibiting effect on the MIE of UPR dust cloud. The calculated MIE of UPR dust cloud increased from 10 mJ to 998 mJ when the mass fractions of APP increased to 30 wt%. Furthermore, the MIT of UPR dust cloud increased with the increase of the mass fractions of APP. When the mass fraction of APP increased to 80 wt%, the MIT increased by 290°C. The suppression mechanism of APP was studied according to thermogravimetry (TG) and differential scanning calorimetry (DSC) tests. Thermal analysis results showed that the addition of APP could increase the thermal stability of UPR. The suppression mechanism was reflected on the consumption of H and OH radicals.

中文翻译：

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聚磷酸铵对不饱和聚酯树脂粉尘爆炸特性抑制作用的实验研究

不同质量分数的聚磷酸铵（APP）对最大爆炸压力（P _max），爆炸指数（K _st），研究了不饱和聚酯树脂（UPR）粉尘的最小着火能量（MIE）和最小着火温度（MIT）。结果表明，随着APP质量分数的增加，UPR粉尘的爆炸强度和着火敏感性逐渐降低。存在最小惰性浓度（MIC），并且通过60wt％的APP可以完全抑制UPR粉尘的爆炸。此外，APP对UPR尘埃云的MIE有很大的抑制作用。当APP的质量分数增加到30 wt％时，UPR尘云的MIE计算值从10 mJ增加到998 mJ。此外，UPR尘云的MIT随着APP质量分数的增加而增加。当APP的质量分数增加到80wt％时，MIT增加了290℃。通过热重（TG）和差示扫描量热（DSC）试验研究了APP的抑制机理。热分析结果表明，添加APP可以提高UPR的热稳定性。抑制机制反映在H和OH自由基的消耗上。