The current study is directed towards the evaluation of thermal stability and flame retardancy of the epoxy resin hexaglycidyl cyclotriphosphazene (HGCP) cured with 4,4′-methylene dianiline (MDA) and its polymer composite reinforced with bisphenol-A diglycidyl ether (DGEBA) by means of experimental, computational, and statistical approaches. The thermal properties of the polymer materials DGEBA-MDA (M1), HGCP-MDA (M2), and their mixture DGEBA-20%HGCP-MDA (M3) were evaluated using differential scanning calorimetry (DSC) and thermogravimetry–infrared spectroscopy (TG-FTIR) coupled analysis. The morphology was studied by scanning electron microscopy–energy dispersive X-ray analysis (SEM–EDX). The vertical flammability test was done used for the evaluation of the flame retardancy. The temperatures of exothermic peak (T_o) of the polymer materials M1, M2 and M3 were 95 °C, 77 °C and 93 °C, respectively. The results revealed that the addition of 20% of HGCP enhances the thermal stability compared to DGEBA and provides a DGEBA UL-94 V0 rating. SEM–EDX analysis showed that HGCP promotes the foaming and expansion of the coal as well as improved the gullies on the coal surface. Heteroskedasticity and autocorrelation consistent (HAC) covariance were performed to combine the results of the thermal degradation of the examined epoxy resins as a function of E_HOMO and E_LUMO, which were obtained from the optimized structure of the epoxy resins using the density functional theory. Consequently, the HAC model was validated by comparing the predicted theoretical results with experimental thermal degradation of the serial of compounds studied.

Graphic abstract

中文翻译：

---

含有环三磷腈的膨胀型环氧树脂的阻燃性：实验、计算和统计研究

目前的研究旨在评估用 4,4'-亚甲基二苯胺 (MDA) 固化的环氧树脂六缩水甘油基环三磷腈 (HGCP) 及其用双酚 A 二缩水甘油醚 (DGEBA) 增强的聚合物复合材料的热稳定性和阻燃性。实验、计算和统计方法。使用差示扫描量热法 (DSC) 和热重-红外光谱法 (TG -FTIR) 耦合分析。通过扫描电子显微镜 - 能量色散 X 射线分析（SEM-EDX）研究形貌。使用垂直可燃性测试来评价阻燃性。放热峰温度 ( T_o ) 聚合物材料 M1、M2 和 M3 分别为 95°C、77°C 和 93°C。结果表明，与 DGEBA 相比，添加 20% 的 HGCP 提高了热稳定性，并提供了 DGEBA UL-94 V0 等级。SEM-EDX 分析表明，HGCP 促进了煤的发泡和膨胀，并改善了煤表面的冲沟。进行异方差和自相关一致 (HAC) 协方差以结合作为E _HOMO和E _LUMO函数的所检测环氧树脂的热降解结果，这是使用密度泛函理论从环氧树脂的优化结构中获得的。因此，通过将预测的理论结果与所研究的一系列化合物的实验热降解进行比较，验证了 HAC 模型。

图形摘要