Kong Fanbei, Nie Baisheng, Han Chao, Zhao Dan, Hou Yanan, Xu Yuxuan
School of Resource and Safety Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
Materials (Basel). 2022 Aug 29;15(17):5977. doi: 10.3390/ma15175977.
Banana peel powder (BPP) was used to prepare poly(lactic acid) (PLA) bio-based composites and the flame retardancy was enhanced by introducing silica-gel microencapsulated ammonium polyphosphate (MCAPP). The results showed that the limiting oxygen index (LOI) of PLA containing 15 wt % BPP was 22.1% and just passed the UL-94 V-2 rate. Moreover, with the introduction of 5 wt % MCAPP and 15 wt % BPP, the PLA composite had a higher LOI value of 31.5%, and reached the UL-94 V-0 rating, with self-extinguishing and anti-dripping abilities. The PLA/M5B15 also had a lower peak heat release rate (296.7 kW·m), which was 16% lower than that of the PLA/B15 composite. Furthermore, the synergistic effects between MCAPP and BPP impart better thermal stability to PLA composites. According to the investigation of the char residue and pyrolysis gaseous products, MCAPP with BPP addition is beneficial to the formation of a higher quality char layer in the solid phase but also plays the flame retardant effect in the gas phase. This work provides a simple and efficient method to solve the high cost and flammability issues of PLA composites.
香蕉皮粉（BPP）被用于制备聚乳酸（PLA）基生物复合材料，通过引入硅胶微胶囊化聚磷酸铵（MCAPP）提高了其阻燃性能。结果表明，含15 wt% BPP的PLA的极限氧指数（LOI）为22.1%，仅通过了UL-94 V-2等级。此外，引入5 wt% MCAPP和15 wt% BPP后，PLA复合材料的LOI值更高，为31.5%，达到了UL-94 V-0等级，具有自熄和抗滴落能力。PLA/M5B15的峰值热释放速率也较低（296.7 kW·m），比PLA/B15复合材料低16%。此外，MCAPP和BPP之间的协同作用使PLA复合材料具有更好的热稳定性。通过对残炭和热解气态产物的研究发现，添加BPP的MCAPP有利于在固相中形成质量更高的炭层，同时在气相中也起到阻燃作用。这项工作提供了一种简单有效的方法来解决PLA复合材料成本高和易燃的问题。
