Zhu Kai, Wang Yunhe, Tang Daquan, Wang Qiang, Li Haihang, Huang Yadong, Huang Zhiyi, Wu Ke
College of Quality and Safety Engineering, China Jiliang University, Hangzhou 310018, China.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China.
Materials (Basel). 2019 Mar 8;12(5):801. doi: 10.3390/ma12050801.
The flame retardancy of asphalt binders with layered double hydroxides (LDHs) was investigated using limiting oxygen index (LOI) and cone calorimeter tests. The flame-retardant mechanism of the LDHs was also studied with thermogravimetry and differential scanning calorimetry (TG⁻DSC), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The cone calorimeter testing results indicated that 2 wt.% of the LDHs can decease the peak heat and smoke release rate of asphalt binders. Because a low dose of LDHs can be well dispersed in asphalt binder and favor the formation of polyaromatic structures during combustion, the thermal oxidation resistance and compactness of the char layer can be improved. The LOI of asphalt binder can be increased and the heat and smoke release during combustion can be decreased with 25 wt.% LDHs. The decomposition of LDHs can absorb the heat release of the initial two stages of asphalt combustion and reduce the burning rate of asphalt. Due to the loss of loosely bound water in the LDHs during the blending process and the decrease of dispersibility at a high LDH dose, the improvement of thermal stability is limited.
采用极限氧指数（LOI）和锥形量热仪试验研究了含层状双氢氧化物（LDHs）的沥青结合料的阻燃性能。还通过热重分析和差示扫描量热法（TG⁻DSC）、扫描电子显微镜（SEM）和X射线光电子能谱（XPS）研究了LDHs的阻燃机理。锥形量热仪测试结果表明，2 wt.%的LDHs可降低沥青结合料的峰值热释放和烟雾释放速率。由于低剂量的LDHs能很好地分散在沥青结合料中，并有利于燃烧过程中多环芳烃结构的形成，因此可提高炭层的抗氧化性和致密性。加入25 wt.%的LDHs可提高沥青结合料的LOI，并减少燃烧过程中的热释放和烟雾释放。LDHs的分解可吸收沥青燃烧前两个阶段的热释放，降低沥青的燃烧速率。由于在共混过程中LDHs中松散结合水的损失以及高剂量LDHs时分散性的降低，热稳定性的提高受到限制。
