Wu Xiaolu, Qin Zhaolu, Zhang Xiang, Yu Zhenfei, Zhang Wenchao, Yang Rongjie, Li Dinghua
National Engineering Research Center of Flame Retardant Materials, School of Materials, Beijing Institute of Technology, Beijing 100081, China.
School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China.
Nanomaterials (Basel). 2022 Feb 11;12(4):606. doi: 10.3390/nano12040606.
A novel composite and functional micro-nanometer particle is designed by the hydrolysis of aluminium isopropoxide on the surface of ammonium polyphosphate (APP) to prepare surface nanostructured ammonium polyphosphate (NSAPP). NSAPP is characterised by XPS, XRF, SEM, water solubility tests, and TGA. Results indicate that nanosized aluminium hydroxide is deposited on the surface of NSAPP, which enhanced its water resistance and thermostability. Then, APP and NSAPP coupled with dipentaerythritol (DPER) is used for the flame retardant of polypropylene (PP). The limiting oxygen index (LOI) value of the PP/DPER/NSAPP composite is higher than that of PP/DPER/APP. Besides, the UL 94 vertical burning test of PP/DPER/NSAPP composites can reach the V-0 rating easily. According to the study of the combustion behaviour of FR-PP composites, NSAPP contributes to form a dense and multi-layered char in the combustion process. Thus, such an intumescent char with a ceramic-like, continuous, and dense structure over the PP matrix protects the underlying matrix and enhances the thermal stability of the condensed phase, thereby improving the flame retardant performance of FR-PP.
通过异丙醇铝在聚磷酸铵（APP）表面水解制备表面纳米结构化聚磷酸铵（NSAPP），设计了一种新型复合功能微纳米粒子。通过XPS、XRF、SEM、水溶性测试和TGA对NSAPP进行了表征。结果表明，纳米氢氧化铝沉积在NSAPP表面，提高了其耐水性和热稳定性。然后，将APP和NSAPP与二季戊四醇（DPER）结合用于聚丙烯（PP）的阻燃。PP/DPER/NSAPP复合材料的极限氧指数（LOI）值高于PP/DPER/APP。此外，PP/DPER/NSAPP复合材料的UL 94垂直燃烧试验很容易达到V-0等级。根据对FR-PP复合材料燃烧行为的研究，NSAPP有助于在燃烧过程中形成致密的多层炭。因此，这种在PP基体上具有类似陶瓷、连续且致密结构的膨胀炭保护了下层基体，提高了凝聚相的热稳定性，从而改善了FR-PP的阻燃性能。
