Li Fangli, Huang Ziqin, Liu Changjiang, Yang Meini, Wu Jixiang, Rao Wenhui, Yu Chuanbai
Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
RSC Adv. 2024 Mar 11;14(12):8204-8213. doi: 10.1039/d4ra00166d. eCollection 2024 Mar 6.
Currently, additively efficient flame retardants are being developed to enhance the smoke suppression, flame retardancy, and thermal properties of composite materials. To this end, the current study designed and prepared a novel P/N/Si/Zn-containing organic-inorganic hybrid denoted as APHZ. Its inorganic part was 2-methylimidazole zinc salt (ZIF-8), which improved its smoke suppression and catalytic carbonization. The organic part (P/N/Si-containing compound) promoted its flame retardancy and interfacial compatibility between APHZ and epoxy resin (EP). The test results revealed that EP/APHZ-3 composites achieved a V-0 rating and a notable LOI value of 30.7% when introducing 3 wt% APHZ into the EP matrix. Cone calorimetry tests (CCT) further demonstrated that the average heat release rate (av-HRR), total smoke production (TSP), and CO production (COP) of EP/APHZ-3 were reduced by 23.3%, 14.0%, and 21.1%, respectively. Meanwhile, the char residual was increased by 60.6%, as compared to pure EP. Furthermore, the flame-retardant mechanism of EP/APHZ composites was investigated by the XPS, TG-FTIR, and Raman spectroscopy techniques. The observed synergistic effect of the imidazole skeleton ZIF-8 and P/N/Si-containing compound in APHZ facilitated the generation of a dense multi-element char layer, with the condensed phase flame-retardant mechanism playing a dominant role. These findings contribute to developing and designing high-performance flame-retardant EP.
目前，人们正在研发具有加和增效作用的阻燃剂，以提高复合材料的抑烟性、阻燃性和热性能。为此，本研究设计并制备了一种新型的含磷/氮/硅/锌有机-无机杂化物，命名为APHZ。其无机部分为2-甲基咪唑锌盐（ZIF-8），可提高其抑烟性和催化碳化性能。有机部分（含磷/氮/硅化合物）促进了其阻燃性以及APHZ与环氧树脂（EP）之间的界面相容性。测试结果表明，当在EP基体中引入3 wt%的APHZ时，EP/APHZ-3复合材料达到了V-0等级，极限氧指数（LOI）值显著达到30.7%。锥形量热测试（CCT）进一步表明，EP/APHZ-3的平均热释放速率（av-HRR）、总产烟量（TSP）和一氧化碳产量（COP）分别降低了23.3%、14.0%和21.1%。同时，与纯EP相比，残炭量增加了60.6%。此外，通过X射线光电子能谱（XPS）、热重-傅里叶变换红外光谱（TG-FTIR）和拉曼光谱技术研究了EP/APHZ复合材料的阻燃机理。观察到的APHZ中咪唑骨架ZIF-8与含磷/氮/硅化合物的协同效应促进了致密多元素炭层的生成，凝聚相阻燃机理起主导作用。这些发现有助于高性能阻燃EP的开发和设计。
