Al(H2PO2)3/聚氨酯弹性体复合材料的制备及阻燃性能

采用熔融共混技术，将Al（H₂PO₂）₃引入聚氨酯热塑性弹性体，制备了一系列次磷酸铝/聚氨酯弹性体复合材料（Al（H₂PO₂）₃/TPU）。采用极限氧指数（LOI）、垂直燃烧（UL-94）、锥形量热测试、TG和SEM研究了Al（H₂PO₂）₃对Al（H₂PO₂）₃/TPU复合材料阻燃性能及热稳定性的影响，采用力学测试研究Al（H₂PO₂）₃对其力学性能的影响。阻燃测试表明，Al（H₂PO₂）₃可以有效提高Al（H₂PO₂）₃/TPU复合材料的阻燃性能。当Al（H₂PO₂）₃添加量为20wt%时，Al（H₂PO₂）₃/TPU复合材料UL-94级别达到V-0级，LOI达到30.5vol%。热重测试表明，Al（H₂PO₂）₃的加入会导致复合材料热分解温度降低，但其残炭率有明显升高。锥形量热测试表明，Al（H₂PO₂）₃的加入有效降低复合材料热释放速率峰值（pHRR）和总热释放（THR），并明显提高其火灾安全性能，其中20wt% Al（H₂PO₂）₃/TPU的pHRR和THR相对纯TPU分别下降65.7%和20.2%。SEM表明，Al（H₂PO₂）₃/TPU复合材料炭渣致密性有明显提高。在此基础上，采用TGA-FTIR联用分析Al（H₂PO₂）₃/TPU复合材料阻燃机制，研究发现，Al（H₂PO₂）₃在燃烧过程中可以有效促进TPU裂解产物成炭，降低可燃性气体生成量，从而提高复合材料阻燃性能。

Preparation and flame retardant properties of Al(H2PO2)3/thermoplastic polyurethane composites

Al(H₂PO₂)₃ was introduced to prepare a series of Al(H₂PO₂)₃/thermoplastic polyurethane composites (Al(H₂PO₂)₃/TPU) by melting blending technology. The flame retardancy and thermal stability of Al(H₂PO₂)₃/TPU composites were respectively investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimeter, TG and SEM, the mechanical test was applied to research the effect of Al(H₂PO₂)₃ content on the mechanical properties of Al(H₂PO₂)₃/TPU composites. Flame retardancy results show that Al(H₂PO₂)₃ can effectively enhance the flame retardancy of Al(H₂PO₂)₃/TPU composites. 20wt% Al(H₂PO₂)₃ makes Al(H₂PO₂)₃/TPU composites UL-94 reach V-0 rating with LOI of 30.5vol%. TG test reveals that loading of Al(H₂PO₂)₃ will decrease the decomposition temperature of the composites while significantly enhance the char residue of Al(H₂PO₂)₃/TPU composites. The cone calorimeter results show that Al(H₂PO₂)₃ can significantly decrease the peak of heat release rate (pHRR) and total heat release (THR) of Al(H₂PO₂)₃/TPU composites, and increase the fire safety of the composites. pHRR and THR values of Al(H₂PO₂)₃/TPU composites with 20wt% Al(H₂PO₂)₃ loading are decreased 65.7% and 20.2% respectively compared with virgin TPU. SEM test indicates that char residue of Al(H₂PO₂)₃/TPU composites are significantly enhanced. TGA-FTIR was used to investigate flame retardant mechanism of Al(H₂PO₂)₃/TPU composites, which indicates that Al(H₂PO₂)₃ could promote the char formation of volatilized products of TPU molecular in combustion process, and reduce the production of combustible gas and enhance the flame retardancy of Al(H₂PO₂)₃/TPU composites.