Fang Minghui, Qian Jun, Wang Xuezhi, Chen Zhong, Guo Ruilin, Shi Yifeng
Key Laboratory of Specially Functional Polymeric Materials and Related Technology of the Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
Hangzhou Rongfang Pressure Sensitive New Material Co., Ltd, Shanghai 200237, China.
ACS Omega. 2021 Mar 1;6(10):7094-7105. doi: 10.1021/acsomega.1c00076. eCollection 2021 Mar 16.
A novel flame retardant (TDA) containing phosphorus, nitrogen, and silicon was synthesized successfully via a controllable ring-opening addition reaction between 1,3,5-triglycidyl isocyanurate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 3-aminopropyltriethoxysilane, and TDA was then blended with diglycidyl ether of bisphenol A to prepare flame-retardant epoxy resins (EPs). The chemical structure and components of TDA were confirmed by Fourier transform infrared (FTIR) spectra, P nuclear magnetic resonance, and X-ray photoelectron spectroscopy. Thermogravimetric analysis results indicated that after the introduction of TDA, cured EP maintained good thermal stability with a minimum initial decomposition temperature of 337.6 °C, and the char yields of a EP/TDA-5 sample significantly increased by 76.2% compared with that of the neat EP thermoset. Additionally, with the addition of 25.0 wt % TDA (1.05 wt % phosphorus loading), the limited oxygen index value of cured EP increased from 22.5% of pure EP to 33.4%, and vertical burning V-0 rating was easily achieved. Meanwhile, after the incorporation of TDA, the total heat release and total smoke production of the EP/TDA-5 sample obviously reduced by 28.9 and 27.7% in the cone calorimeter test, respectively. Flame-retardant performances and flame-retardant mechanisms were further analyzed by scanning electron microscopy, FTIR, energy-dispersive spectrometry, and pyrolysis gas chromatography/mass spectrometry. The results reveal that the synergistic effect of phosphorus, nitrogen, and silicon plays an excellent flame-retardant role in both gaseous and condensed phases. In addition, the mechanical and dynamic mechanical properties of cured EP thermosets are well maintained rather than destroyed. All the results demonstrate that TDA endows epoxy resin with excellent flame retardancy and possesses great promise in the industrial field.
通过1,3,5-三缩水甘油基异氰脲酸酯、9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物和3-氨丙基三乙氧基硅烷之间可控的开环加成反应，成功合成了一种含磷、氮和硅的新型阻燃剂（TDA），然后将TDA与双酚A二缩水甘油醚共混制备阻燃环氧树脂（EP）。通过傅里叶变换红外（FTIR）光谱、磷核磁共振和X射线光电子能谱确定了TDA的化学结构和成分。热重分析结果表明，引入TDA后，固化的EP保持了良好的热稳定性，最低初始分解温度为337.6℃，EP/TDA-5样品的残炭率与纯EP热固性材料相比显著提高了76.2%。此外，添加25.0 wt%的TDA（磷负载量为1.05 wt%）后，固化EP的极限氧指数值从纯EP的22.5%提高到33.4%，并容易达到垂直燃烧V-0等级。同时，在锥形量热仪测试中，加入TDA后，EP/TDA-5样品的总热释放和总产烟量分别明显降低了28.9%和27.7%。通过扫描电子显微镜、FTIR、能谱和热解气相色谱/质谱进一步分析了阻燃性能和阻燃机理。结果表明，磷、氮和硅的协同作用在气相和凝聚相中都发挥了优异的阻燃作用。此外，固化EP热固性材料的力学和动态力学性能得到了很好的保持，而不是被破坏。所有结果表明，TDA赋予环氧树脂优异的阻燃性，在工业领域具有很大的应用前景。
