Chen Xin, Cui Xinyu, Sun Jun, Li Hongfei, Gu Xiaoyu, Zhang Sheng
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
Int J Biol Macromol. 2025 Mar;293:139184. doi: 10.1016/j.ijbiomac.2024.139184. Epub 2024 Dec 26.
Polylactic acid (PLA) is a bio-recyclable plastic, but its high flammability limits broader applications. Here, a novel flame retardant (Zn-CHP) is synthesized from chitosan (CH), diethylenetriaminepenta (methylenephosphonic) acid (DTPMP), and ZnCl₂ using a simple, solvent-free process. The Zn-CHP additive is melt-blended with PLA, achieving excellent flame retardancy at just 2 wt% loading. The modified PLA exhibits a limiting oxygen index (LOI) of 25.5 % and meets, though minor non-combustible dripping is observed, which cools significantly around 200 °C compared to the untreated PLA. Cone calorimeter tests show that the addition of 2 wt% Zn-CHP reduces the peak heat release rate (pHRR) by 16.8 %, total heat release (THR) by 9.0 %, and fire growth rate by 23.1 %. Importantly, the tensile performance of the PLA is little affected, while the additive accelerates its degradation. We believe this work offers a promising approach to enhancing flame retardancy and promoting faster recycling of PLA.
聚乳酸（PLA）是一种可生物回收的塑料，但其高易燃性限制了其更广泛的应用。在此，一种新型阻燃剂（Zn-CHP）由壳聚糖（CH）、二乙烯三胺五（亚甲基膦酸）（DTPMP）和ZnCl₂通过简单的无溶剂工艺合成。Zn-CHP添加剂与PLA进行熔融共混，仅在2 wt%的添加量下就实现了优异的阻燃性。改性后的PLA极限氧指数（LOI）为25.5%，尽管观察到有少量不可燃液滴，但与未处理的PLA相比，在200°C左右显著冷却。锥形量热仪测试表明，添加2 wt%的Zn-CHP可使热释放峰值速率（pHRR）降低16.8%，总热释放（THR）降低9.0%，火灾增长速率降低23.1%。重要的是，PLA的拉伸性能几乎没有受到影响，而该添加剂加速了其降解。我们相信这项工作为提高PLA的阻燃性和促进其更快回收提供了一种有前景的方法。
