Abstract Herein, we report the development of multiphase epoxy-based nanocomposite blends with enhanced fracture toughness and controlled microstructure. The blends are based on bifunctional and tetrafunctional epoxy resins, suitable for a wide range of applications particularly as matrices for advanced high temperature fibre reinforced composites with glass transition temperatures exceeding 200 degrees Celsius. The multiphase blends comprise nanoscale (carbon nanotubes) and microscale (phase separating thermoplastic) inclusions which together form unique multiscale morphologies capable of dissipating crack energy through different energy absorption mechanisms. This work provides, for the first time, an in-depth investigation of the interactions between the nano- and micro-scale toughness modifiers which under appropriate conditions lead to a synergistic enhancement in the fracture toughness of the resin. A secondary agglomeration of carbon nanotubes during curing was shown to be suppressed by the phase separating thermoplastic particles, leading to a well dispersed state justifying the synergistic increase in fracture toughness of the resulting blends. The molecular architecture of the epoxy matrix, in particular, the number of epoxide functional groups, was shown to be of significant importance in determining the final microstructure of the modified blends following curing reaction.

中文翻译：

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热塑性塑料和碳纳米管改性多相环氧树脂基质中断裂韧性的协同增强

摘要在此，我们报告了具有增强的断裂韧性和可控微观结构的多相环氧基纳米复合材料的开发。该共混物基于双官能和四官能环氧树脂，适用于广泛的应用，特别是作为玻璃化转变温度超过 200 摄氏度的高级高温纤维增强复合材料的基质。多相混合物包含纳米级（碳纳米管）和微米级（相分离热塑性塑料）夹杂物，它们共同形成独特的多级形态，能够通过不同的能量吸收机制耗散裂纹能量。这项工作首次提供了 深入研究纳米级和微米级韧性改性剂之间的相互作用，这些改性剂在适当条件下会协同提高树脂的断裂韧性。碳纳米管在固化过程中的二次聚集被相分离的热塑性颗粒抑制，导致良好的分散状态，证明所得共混物断裂韧性的协同增加是合理的。环氧基质的分子结构，特别是环氧化物官能团的数量，在确定固化反应后改性共混物的最终微观结构方面具有重要意义。碳纳米管在固化过程中的二次聚集被相分离的热塑性颗粒抑制，导致良好的分散状态，证明所得共混物断裂韧性的协同增加是合理的。环氧基质的分子结构，特别是环氧化物官能团的数量，在确定固化反应后改性共混物的最终微观结构方面具有重要意义。碳纳米管在固化过程中的二次聚集被相分离的热塑性颗粒抑制，导致良好的分散状态，证明所得共混物断裂韧性的协同增加是合理的。环氧基质的分子结构，特别是环氧化物官能团的数量，在确定固化反应后改性共混物的最终微观结构方面具有重要意义。