Preparation of fire safety and high mechanical strength epoxy resin (EP) has become a hot topic for its valuable applications in construction and other fields. Here, bis-2-aminobenzimidazole-modified phenyl phosphonates (PP-BMI) with symmetric structures were synthesized by a simple chemical modification strategy, and its fine structure and composition have been thoroughly characterized. Due to the multifaceted functions of PP-BMI in both gaseous and condensed phases, EP composite with 5 wt% PP-BMI reached a UL-94 V-0 rating and high LOI of 34.3 %. The excellent fire safety of EP/5PP-BMI was further verified with a significant reduction of 57 %, 52 % and 46 % in peak heat release rate (PHRR), total heat release (THR) and peak CO production (P-COP), respectively, compared to the original EP. The flame retardancy of PP-BMI on EP can be attributed to the dilution of non-combustion gases, free radical trapping and catalytic charring functions. More importantly, PP-BMI can further enhance the mechanical properties of EP, which is closely related to the interaction between PP-BMI and EP matrix. Furthermore, EP/PP-BMI composites have good resistance to acids and alkalis, ensuring long-lasting flame retardancy and mechanical properties. This work provides a new strategy for realizing epoxy composites with high fire safety and excellent mechanical properties in construction and multifaceted areas.

中文翻译：

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由双苯并咪唑引发的苯基膦酸实现防火安全性和高机械强度环氧树脂


防火、高机械强度环氧树脂 （EP） 的制备因其在建筑等领域的重要应用而成为热门话题。在这里，通过简单的化学修饰策略合成了具有对称结构的双-2-氨基苯并咪唑修饰的苯基膦酸盐 （PP-BMI），并对其精细结构和组成进行了彻底表征。由于 PP-BMI 在气相和凝聚相中的多方面功能，PP-BMI 含量为 5 wt% 的 EP 复合材料达到了 UL-94 V-0 等级和 34.3% 的高 LOI。与原始 EP 相比，EP/5PP-BMI 的峰值热释放率 （PHRR）、总热释放 （THR） 和峰值 CO 产生 （P-COP） 分别显著降低了 57%、52% 和 46%，进一步验证了 EP/5PP-BMI 的出色防火安全性。PP-BMI 对 EP 的阻燃性可归因于非燃烧气体的稀释、自由基捕获和催化炭化功能。更重要的是，PP-BMI 可以进一步增强 EP 的力学性能，这与 PP-BMI 和 EP 基体之间的相互作用密切相关。此外，EP/PP-BMI 复合材料具有良好的耐酸和耐碱性能，确保持久的阻燃性和机械性能。这项工作为在建筑和多面领域实现具有高防火安全性和优异机械性能的环氧树脂复合材料提供了一种新策略。