In this article, a flame retardant microcapsule ammonium polyphosphate microencapsulated by polyurea (POAPP) was successfully synthesized by interfacial polymerization method using ammonium polyphosphate (APP) as core and polyurea as shell. The microencapsulation is observed by scanning electron microscopy and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and hydroscopicity test, which prove the success in synthesizing microencapsulation. When the POAPP is added into rigid polyurethane foam (RPUF), the flame retardant and mechanical properties are investigated using cone calorimeter, limited oxygen index test, and compressive strength test. The PHRR of RPUF‐POAPP20 decreased from 336.52 kW/m² (Ref. RPUF) to 203.84 kW/m² and the THR of RPUF‐POAPP20 was only 7.6 MJ/m², which is 33.9% lower than that of Ref. RPUF. Furthermore, the limiting oxygen index of RPUF‐POAPP20 reaches 24.8%, which increased by 36.3% compared to Ref. RPUF. Whereas the maximum compressive strength of RPUF‐POAPP5 was 7.46 MPa, which is higher than that of RPUF‐APP5.

中文翻译：

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微囊化聚磷酸铵对硬质聚氨酯泡沫塑料阻燃性能和力学性能的影响

本文以聚磷酸铵（APP）为核，聚脲为壳，通过界面聚合法成功地合成了聚脲（POAPP）微囊化的阻燃微胶囊聚磷酸铵。通过扫描电子显微镜观察微囊，并通过傅里叶变换红外光谱，热重分析和吸湿性测试对其进行表征，证明了合成微囊的成功。当将POAPP添加到硬质聚氨酯泡沫（RPUF）中时，使用锥形量热仪，极限氧指数测试和抗压强度测试来研究其阻燃性和机械性能。RPUF-POAPP20的PHRR从336.52 kW / m ²（参考RPUF）降至203.84 kW / m ²RPUF-POAPP20的THR仅7.6 MJ / m ²，比Ref。低33.9％。RPUF。此外，RPUF-POAPP20的极限氧指数达到24.8％，与Ref.3相比增加了36.3％。RPUF。RPUF-POAPP5的最大抗压强度为7.46 MPa，高于RPUF-APP5的最大抗压强度。