磷腈/三嗪双基分子复配阻燃聚乳酸

将磷腈/三嗪双基分子阻燃剂（HTTCP）分别与六苯氧基环三磷腈（HPCTP）和季戊四醇磷酸酯（PEPA）按不同配比复配，采用熔融共混法制备了阻燃聚乳酸（PLA）的复合材料。采用热失重分析仪、极限氧指数仪、垂直燃烧试验箱和锥形量热仪研究了2种复配阻燃体系及其配比对PLA阻燃复合材料热稳定性和阻燃性能的影响，并采用扫描电子显微镜对材料的残炭形貌进行了分析，探究了其阻燃机理。结果表明，PEPA/HTTCP复配阻燃剂的阻燃效果优于HPCTP/HTTCP复配阻燃剂。当PEPA/HTTCP的质量比为3/1，总添加量为20 %时，阻燃PLA的极限氧指数最高，为27.2 %，热释放速率峰值、平均热释放速率以及热释放总量达到最小值，且能够达到UL 94 V-0级。

Poly(lactic acid) Flame Retarded by Phosphazene-triazine Bi-groups Compound

A novel flame retardant based on phosphazene and triazine groups (HTTCP) was used to modify poly(lactic acid) (PLA) by a combination of hexaphenoxycyclotriphosphazene (HPCTP) and pentaerythritol octahydrogen tetraphosphate (PEPA) via a melt blending method. Thermogravimetric analysis, limiting oxygen index (LOI), vertical burning experiment and cone calorimetry were conducted to investigate the effect of different flame retardants and their weight ratios on thermal stability and flame retardant properties of PLA matrix composites. Moreover, the morphology of residual char was analyzed by scanning electron microscopy, and the flame retardant mechanisms were investigated. The results indicated that PEPA/HTTCP system exhibited a better flame retardant effect on HPCTP/HTTCP one due to its excellent protective and barrier effect. The composites gained a maximum LOI of 27.2 vol % with the addition of 20 wt % flame retardants at PEPA and HTTCP mass ratio of 3∶1. Furthermore, their heat release rate, average heat release rate and total heat release also reached the minimum values, and meanwhile, the composite achieved a UL94 V-0 classification in the vertical combustion experiment.