Zhu Shiyang, Jiang Zhaoliang, Liu Zongsheng, Zheng Yi, Ge Bangdong, Ma Meng, Chen Si, He Huiwen, Shi Yanqin, Zhu Yulu, Wang Xu
College of Materials Science and Engineering, Zhejiang Key Laboratory of Plastic Modification and Processing Technology, Zhejiang University of Technology, Hangzhou, 310014, PR China.
College of Materials Science and Engineering, Zhejiang Key Laboratory of Plastic Modification and Processing Technology, Zhejiang University of Technology, Hangzhou, 310014, PR China; State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, PR China.
Int J Biol Macromol. 2025 Sep 5;327(Pt 2):147497. doi: 10.1016/j.ijbiomac.2025.147497.
The flammability and poor ultraviolet (UV) aging resistance of polylactic acid (PLA) limit its applications outdoors and in fields requiring flame retardancy. To address these limitations, this study designed ammonium polyphosphate (APP) as the core, the biopolymer chitosan (CS) as the inner shell, and lignin (LK) as the outer shell. CS and LK are deposited on the surface of APP via electrostatic interaction in the aqueous phase to prepare a core-shell structure flame retardant APP@CS@LK with anti-UV aging properties. The resulting PLA/APP@CS@LK composite achieved a UL-94 V-0 rating in vertical burning tests. The limiting oxygen index (LOI) of neat PLA was 19.5 %, which increased to 30.7 % upon incorporation of 10 wt% APP@CS@LK. Furthermore, cone calorimeter data revealed that compared to pure PLA, the peak heat release rate (PHRR) of PLA/APP@CS@LK was reduced by 23.5 %, while CO₂ and CO emissions were reduced by 31 % and 74 %, respectively. Simultaneously, the phenolic hydroxyl groups in LK act as free radical scavengers, imparting exceptional UV resistance. The composite blocked nearly 99 % of UV light (UPF 64.8). This study provides a safe and green preparation method of multifunctional flame retardant, which can be used to prepare flame retardant PLA composites with anti-ultraviolet aging property, thereby expanding the potential applications of PLA.
聚乳酸（PLA）的易燃性和较差的抗紫外线（UV）老化性能限制了其在户外和需要阻燃的领域的应用。为了解决这些限制，本研究设计了以聚磷酸铵（APP）为核心、生物聚合物壳聚糖（CS）为内壳、木质素（LK）为外壳的结构。CS和LK通过水相中的静电相互作用沉积在APP表面，制备出具有抗紫外线老化性能的核壳结构阻燃剂APP@CS@LK。所得的PLA/APP@CS@LK复合材料在垂直燃烧试验中达到了UL-94 V-0等级。纯PLA的极限氧指数（LOI）为19.5%，加入10 wt%的APP@CS@LK后提高到30.7%。此外，锥形量热仪数据显示，与纯PLA相比，PLA/APP@CS@LK的峰值热释放速率（PHRR）降低了23.5%，同时CO₂和CO排放量分别降低了31%和74%。同时，LK中的酚羟基作为自由基清除剂，赋予了优异的抗紫外线性能。该复合材料阻挡了近99%的紫外线（UPF 64.8）。本研究提供了一种安全绿色的多功能阻燃剂制备方法，可用于制备具有抗紫外线老化性能的阻燃PLA复合材料，从而扩大PLA的潜在应用范围。
