Aluminum hypophosphite (AHP) is an effective phosphorus-containing flame retardant. But AHP also has fire risk that it will decompose and release phosphine which is spontaneously flammable in air and even can form explosive mixtures with air in extreme cases. In this paper, AHP has been microencapsulated by melamine cyanurate (MCA) to prepare microencapsulated aluminum hypophosphite (MCAHP) with the aim of enhancing the fire safety in the procedure of production, storage and use. Meanwhile, MCA was a nitrogen-containing flame retardant that can work with AHP via the nitrogen-phosphorus synergistic effect to show improved flame-retardant property than other capsule materials. After microencapsulation, MCA presented as a protection layer inhibit the degradation of AHP and postpone the generation of phosphine. Furthermore, the phosphine concentration could be effectively diluted by inert decomposition products of MCA. These nonflammable decomposition products of MCA could separate phosphine from air delay the oxidizing reaction with oxygen and decrease the heat release rate, which imply that the fire safety of AHP has been improved. Furthermore, MCAHP was added into polyamide 6 to prepare flame retardant polyamide 6 composites (FR-PA6) which show good flame retardancy.

中文翻译：

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次磷酸铝微囊化以提高其安全性，并应用于阻燃聚酰胺6。

次磷酸铝（AHP）是一种有效的含磷阻燃剂。但是AHP还具有着火的危险，它将分解并释放出在空气中可自燃的磷化氢，在极端情况下甚至会与空气形成爆炸性混合物。本文通过三聚氰胺氰尿酸酯（MCA）对AHP进行微囊化，制备了微囊化的次磷酸铝（MCAHP），目的是在生产，储存和使用过程中提高消防安全性。同时，MCA是一种含氮阻燃剂，可通过氮-磷协同作用与AHP协同工作，显示出比其他胶囊材料更高的阻燃性。微囊化后，作为保护层的MCA抑制了AHP的降解并推迟了膦的生成。此外，MCA的惰性分解产物可以有效地稀释膦的浓度。MCA的这些不可燃分解产物可以将膦与空气分离，从而延迟了与氧气的氧化反应并降低了放热速率，这表明AHP的防火安全性得到了提高。此外，将MCAHP添加到聚酰胺6中以制备显示出良好阻燃性的阻燃性聚酰胺6复合材料（FR-PA6）。