Abstract Epoxy-based composites are one of the most promising lightweight materials, while the obtention of fire safety usually accompanies with the sacrifice of mechanical properties. Herein, efforts were paid to coordinate the mechanical performance and the fire safety of the epoxy-based composite. Nanodiamond (ND) was modified with P species, Cu species, and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) step by step, to strengthen the mechanical performance and further optimize the fire safety of the ammonium polyphosphate (APP)/epoxy composite simultaneously. The developed composite successfully improved the APP/epoxy composite on tensile properties, glass transition temperature (Tg) and heat release performance in the fire, meanwhile, kept the advantages on storage modulus and other fire safety performances (vertical burning test, limited oxygen index (LOI) and cone calorimeter). After studying the changes to ND and the composite performances that brought about by the every-step modification to ND, the nice improvement on heat release performance was supposed to be mainly contributed to the improved charring effect and the free radical scavenging effect of TND, and the improved tensile properties were due to the formed Cu N bond in the curing process that connected Cu species, ND and epoxy matrix together. Model experiments were designed to further verify the reinforcing mechanism.

中文翻译：

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通过功能化纳米金刚石协调环氧树脂的机械性能和防火安全

摘要 环氧基复合材料是最有发展前景的轻质材料之一，但为了防火安全，往往伴随着力学性能的牺牲。在此，努力协调环氧基复合材料的机械性能和防火安全性。纳米金刚石 (ND) 逐步用 P 物种、Cu 物种和 (2,2,6,6-四甲基哌啶-1-基)氧基 (TEMPO) 进行改性，以增强机械性能并进一步优化其防火安全性。聚磷酸铵（APP）/环氧树脂复合材料。开发的复合材料成功地提高了 APP/环氧树脂复合材料的拉伸性能、玻璃化转变温度 (Tg) 和火灾中的热释放性能，同时保持了储能模量和其他防火安全性能（垂直燃烧试验、有限氧指数（LOI）和锥形量热仪）。通过研究ND的变化和ND的每一步改性所带来的复合性能，散热性能的良好提高主要归功于TND的炭化效果和自由基清除效果的提高，并且拉伸性能的改善是由于在固化过程中形成的 Cu N 键将 Cu 物质、ND 和环氧树脂基体连接在一起。设计模型实验以进一步验证增强机制。热释放性能的良好改善主要归因于TND的炭化效果和自由基清除效果的改善，拉伸性能的改善是由于在固化过程中形成的Cu N键连接了Cu物种，ND和环氧树脂基体一起。设计模型实验以进一步验证增强机制。热释放性能的良好改善主要归因于TND的炭化效果和自由基清除效果的改善，拉伸性能的改善是由于在固化过程中形成的Cu N键连接了Cu物种，ND和环氧树脂基体一起。设计模型实验以进一步验证增强机制。