Hou Ruyi, Liang Lixu, Jin Yao, Fan Wenqian, Yan Yongbin, Wei Zhaoyang
School of Chemistry and Materials Science, Hubei Engineering University, Xiaogan 432000, China.
School of Materials Science and Engineering, Hubei University, Wuhan 430060, China.
ACS Omega. 2025 Jul 16;10(29):32348-32363. doi: 10.1021/acsomega.5c04512. eCollection 2025 Jul 29.
Layered double hydroxides (LDHs) have attracted more and more attention in the field of flame retardants because of their halogen-free, nontoxic, and excellent smoke suppression properties. However, due to the easy agglomeration and poor compatibility with the polymer matrix, its flame-retardant efficiency was reduced. In this study, a novel flame retardant containing phytic acid-modified LDH (PA-LDH) was prepared for polylactic acid (PLA). The microstructure and properties of PA-LDH were analyzed, and the flame retardancy of PLA composites based on the PA-LDH hybrid system was discussed. The research results indicated that PA-LDH exhibited better dispersion than LDH in PLA, which was favorable for the improvement of its flame retardancy. The PLA composites containing 25 wt % PA-LDH (11.02 wt % phosphorus content) and 8.33 wt % tannic acid (TA) presented 26.9% limiting oxygen index (LOI) value, and its vertical burning grade (UL-94) reached V-0. Furthermore, cone calorimetry results illustrated that compared with pure PLA, its peak heat release rate (PHRR), total heat release rate (THR), and total smoke production (TSP) decreased by 52.1%, 57.9%, and 62.2%, respectively. All of these revealed that PA-modified LDH significantly improved the fire safety of the PLA matrix by increasing barrier effects and catalytic carbonization effects during the combustion process. Moreover, the addition of PA-LDH could increase the crystallinity ( ) and mechanical properties in comparison with the PLA/LDH composite, due to the production of more hydrogen bonds of PA-LDH with PLA.
层状双氢氧化物（LDHs）由于其无卤、无毒且具有优异的抑烟性能，在阻燃剂领域受到了越来越多的关注。然而，由于其易于团聚且与聚合物基体的相容性较差，其阻燃效率有所降低。在本研究中，制备了一种含植酸改性LDH（PA-LDH）的新型阻燃剂用于聚乳酸（PLA）。分析了PA-LDH的微观结构和性能，并讨论了基于PA-LDH杂化体系的PLA复合材料的阻燃性能。研究结果表明，PA-LDH在PLA中的分散性优于LDH，这有利于提高其阻燃性。含有25 wt% PA-LDH（磷含量为11.02 wt%）和8.33 wt%单宁酸（TA）的PLA复合材料的极限氧指数（LOI）值为26.9%，其垂直燃烧等级（UL-94）达到V-0。此外，锥形量热法结果表明，与纯PLA相比，其峰值热释放速率（PHRR）、总热释放速率（THR）和总产烟量（TSP）分别降低了52.1%、57.9%和62.2%。所有这些都表明，PA改性的LDH通过在燃烧过程中增加阻隔效应和催化碳化效应，显著提高了PLA基体的火灾安全性。此外，与PLA/LDH复合材料相比，添加PA-LDH可提高结晶度（ ）和力学性能，这是由于PA-LDH与PLA产生了更多的氢键。
