摘要:
通过在聚磷酸铵(APP)缩聚反应过程中加入钙基纳米蒙脱土(CaMMT), 制备CaMMT/APP复合物, 以提高CaMMT在APP中的分散性, 并提高其热性能。采用FTIR、 XRD、 TGA、 31P核磁共振(31P NMR)以及水溶解性和pH值测试等, 表征了添加不同质量分数的CaMMT和在不同温度下制备得到的CaMMT/APP复合物的结构和性质。测试分析表明: CaMMT/APP中CaMMT是完全剥离的, 表明CaMMT在APP中分散性好。随着复合物中CaMMT含量增加, 复合物中Ⅰ型结晶APP比例提高, APP聚合度下降, 复合物水溶性增大, 起始分解温度降低, 但800 ℃时复合物的残余质量分数更高。当CaMMT的添加量相同时, 添加CaMMT时反应体系的温度越高, 越有利于生成高聚合度的结晶Ⅱ型APP, 复合物的水溶性也降低, 热性能提高, 温度为210 ℃, 复合物在800 ℃的残余质量分数为29.69%, 当温度为300 ℃时, 复合物残余质量分数上升至53.75%。
Abstract:
Calcium nano-montmorillonite(CaMMT)/ammonium polyphosphate(APP)compounds (CaMMT/APP) were prepared when different amounts of CaMMT were added at selected temperatures into the synthetic system of APP, and good dispersion of CaMMT and better thermal properties of the compounds were expected. The compunds were analysed by FTIR, XRD, TGA, 31P nuclear magnetic resonance (31P NMR), and their water solubility and pH were also measured. The completely exfoliated CaMMT is observed in the CaMMT/APP, indicating that CaMMT disperses well in APP. With the increasing content of CaMMT, the amount of APP with crystal form Ⅰ in the compunds increases, the degree of polymerization of APP decreases, and the initial degradation temperature of the compounds decreases, while the water solubilty of the compounds increases. However, higher contents of CaMMT help the compunds yield more residues at 800 ℃. With the same ammount of CaMMT, the higher the temperature, the more APP with crystal form Ⅱ with a higher degree of polymerization, and the water solubility of the compunds effectively decreases, and the thermostability of the compunds can be further enhanced. When CaMMT is added at 210℃, the relative mass of the residue of the compound is 29.69%, which is enhanced to 53.75% when CaMMT is added at 300 ℃.
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