This study investigates the thermal decomposition and fire behavior of zinc phosphinate (ZnP) in combination with low sulphonate content alkali lignin (LS) in a polyamide 11 (PA11) matrix. The influence of ZnP with LS on PA11 was assessed by using thermogravimetric analysis coupled with FTIR spectroscopy (TG-FTIR). Such decomposition products as hydrocarbons, amide and carbonyl units, phenolic and phosphinate compounds control the decomposition. The chemical structure of the condensed phase was evaluated by FTIR measurements carried out on the residues. The fire behavior was investigated using UL 94 vertical flame spread tests and cone calorimetry tests. In the ternary blends, the addition of LS promotes char formation as assessed by TG analyses; furthermore, ZnP contributes to flame inhibition mainly by radical trapping and partially by dilution of fuel, due to phosphinate ions and a small amount of phosphinic acid released in the gas phase. Besides, phosphate compounds are formed in the condensed phase. The combination of LS and ZnP enhanced flame-retardant properties due to the formation of a stable char layer with barrier features.

本研究研究了次膦酸锌（ZnP）与低磺酸盐含量的木质素（LS）在聚酰胺11（PA11）基质中的热分解和燃烧行为。ZnP和LS对PA11的影响通过热重分析和FTIR光谱仪（TG-FTIR）进行评估。诸如烃，酰胺和羰基单元，酚和次膦酸酯化合物之类的分解产物控制分解。冷凝相的化学结构通过对残留物进行的FTIR测量进行评估。使用UL 94垂直火焰蔓延测试和圆锥量热测试研究了燃烧行为。在三元混合物中，通过TG分析评估，添加LS促进了炭的形成。此外，由于次膦酸根离子和气相中释放的少量次膦酸，ZnP主要通过自由基捕获和部分通过稀释燃料来促进火焰抑制。此外，在缩合相中形成磷酸盐化合物。LS和ZnP的结合增强了阻燃性能，原因是形成了具有阻隔功能的稳定炭层。