Abstract：
Aluminum hypophosphite (AHP) has been used as a flame retardant for a long time. Previous studies about AHP employed in flame retardant materials mostly focus on coating, modification, and complex system. It is valuable to explore simple experimental steps to prepare nano hybrids with AHP and metal-organic frameworks (MOFs). We found acidic substances could etch zeolitic imidazolate framework-67 (ZIF-67) to obtain MOF derivatives. Unfortunately, AHP and ZIF-67 could not directly form a hybrid. Therefore, carboxymethylcellulose (CMC) is introduced as a dual function layer (buffer and support). The CMC resists the complete conversion of ZIF-67 etched by phosphoric acid to amorphous cobalt phosphate hydrate (ACP). Meanwhile, CMC containing hydroxyl groups combines with AHP through electrostatic interaction and coordination bonds. A double-layer hollow MOF derivative is synthesized through this one-stone-two-birds strategy. Due to multiple flame retardant elements and unique nanostructure, this MOF derivative endows epoxy (EP) resin with excellent flame retardancy. With 2.0 wt% addition, the peak heat release rate (pHRR) and total heat release (THR) of EP/AHP/ACP@CMC are decreased by 47.8 and 21.0 %, respectively. This study proposes a novel scheme that converts AHP into MOF derivatives as high-performance FRs.
摘要：
次磷酸铝(AHP)作为阻燃剂已经使用了很长时间。以往关于AHP在阻燃材料中应用的研究主要集中在涂层,修改,复杂的系统。探索用AHP和金属有机骨架（MOFs）制备纳米杂化物的简单实验步骤是有价值的。我们发现酸性物质可以蚀刻沸石咪唑酯骨架67（ZIF-67）以获得MOF衍生物。不幸的是,AHP和ZIF-67不能直接形成杂交体。因此,羧甲基纤维素(CMC)作为双功能层(缓冲层和载体)引入。CMC抵抗由磷酸蚀刻的ZIF-67完全转化为无定形磷酸钴水合物(ACP)。同时,含有羟基的CMC通过静电相互作用和配位键与AHP结合。通过这种一石双鸟策略合成了双层空心MOF衍生物。由于多种阻燃元素和独特的纳米结构，这种MOF衍生物赋予环氧（EP）树脂优异的阻燃性。添加2.0wt%时，EP/AHP/ACP@CMC的峰值放热率（pHRR）和总放热（THR）分别降低了47.8和21.0％，分别。本研究提出了一种将AHP转化为MOF衍生物作为高性能FR的新方案。
