有机蒙脱土协同含磷木质素基成炭剂阻燃聚乳酸

将自制含磷木质素基成炭剂（Lig-P）和聚磷酸铵（APP）复配用于制备阻燃聚乳酸（PLA）基复合材料，考察了协效阻燃剂有机蒙脱土（OMMT）对阻燃PLA性能的影响。采用极限氧指数（LOI）仪、垂直燃烧（UL-94）测试仪、锥形量热仪、热失重分析仪分别对Lig-P-APP-OMMT/PLA阻燃复合材料的阻燃性能、热稳定性能和燃烧行为进行了研究。结果发现，OMMT与Lig-P-APP存在明显的协同阻燃作用，当OMMT替代3wt%的Lig-P-APP时，Lig-P-APP-OMMT/PLA阻燃复合材料的LOI由27%增加至32%，UL-94等级由V1级提高至V0级；且Lig-P-APP-OMMT/PLA阻燃复合材料的最大热降解速率有所降低，800℃的残炭量提高了将近50%；此外，OMMT的引入使PLA阻燃复合材料的热释放速率明显降低，热释放速率峰值（PHRR）、烟释放速率峰值（PSPR）及总烟释放量（TSR）分别降低了26.4%、60%及26.3%。OMMT可明显提高阻燃PLA炭层的致密度及石墨化程度。 

Synergistic effect of organic montmorillonite and lignin-based charring agent with phosphorus on flame retardant poly(lactic acid)

The self-made lignin-based charring agent with phosphorus (Lig-P) and ammonium polyphosphate (APP) were used for the preparation of flame retardant poly(lactic acid) (PLA), and organic montmorillonite (OMMT) was also incorporated into flame retardant PLA, and the synergistic effect of OMMT on the flame retardant properties of PLA was studied in detail. The flame retardancy, thermal degradation and fire performance of the Lig-P-APP-OMMT/PLA composites were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetric test and TGA, respectively. The analysis results show that there is significantly synergistic effect between OMMT and Lig-P-APP for Lig-P-APP-OMMT/PLA composites, in which the LOI value of PLA increase from 27% to 32%, accompanied with the PLA passing V-0 rating in UL-94 test at 3wt% of OMMT substitution for Lig-P-APP. The peak thermal degradation rate of Lig-P-APP-OMMT/PLA flame retardant composites reduces, and its charring residue at 800℃ increases by nearly 50%. Cone calorimetry results indicate that the heat release rate of Lig-P-APP-OMMT/PLA flame retardant composites dramatically reduces, and the peak heat release rate (PHRR), the peak smoke produce rate (PSPR) and the total smoke production (TSP) decrease by 26.4%, 60% and 26.3%, respectively with the optimum loading of 3wt% OMMT. The incorporation of OMMT benefits to the formation of much more compact and more graphitic char layer during the combustion of Lig-P-APP-OMMT/PLA flame retardant composites.