Abstract

Epoxy resins are one of the most commonly used class of materials in polymeric composite industry. One of their main weak points is their vulnerability to moist and hot environments. In this paper, the effect of hydrophilic Fe₂O₃ nanoparticles, hydrophobic graphene-oxide nanoplatelets (GONPs) and a hybrid of both was experimentally studied on the moisture absorption and mechanical properties degradation of the nanocomposites. Different weight percentages of nanofillers were used for fabricating the nanocomposite specimens. The neat and nanocomposite specimens were aged in hot deionized water. The gravimetric test results revealed that the Fe₂O₃ nanoparticles and GONPs caused 12.4 and 6.7% reductions in the ultimate moisture uptake of the nanocomposites, respectively. The addition of 1 wt % Fe₂O₃ nanoparticles reduced the moisture diffusion coefficient by 11.7% due to the increased polarity of epoxy, while 0.25 wt % GONPs increased it by 38.5% due to the increased free volume of epoxy. Moreover, the wet Fe₂O₃/epoxy nanocomposites experienced the maximum 28.8 and 52.9% higher strength and stiffness compared to the wet neat epoxy, respectively. GONP/epoxy nanocomposites showed the maximum 22.3 and 13.4% higher values of strength and stiffness compared to the wet neat epoxy.

中文翻译：

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亲水和疏水纳米填料对湿热条件下纳米复合材料吸湿和力学性能降解的影响

摘要

环氧树脂是聚合物复合材料工业中最常用的一类材料。它们的主要弱点之一是它们对潮湿和炎热环境的脆弱性。在本文中，亲水性 Fe ₂ O ₃纳米粒子、疏水性氧化石墨烯纳米片 (GONPs) 以及两者的混合物对纳米复合材料的吸湿性和机械性能退化的影响进行了实验研究。不同重量百分比的纳米填料用于制造纳米复合材料样品。纯样品和纳米复合材料样品在热去离子水中老化。重量测试结果表明，Fe ₂ O ₃纳米颗粒和 GONPs 分别使纳米复合材料的最终吸湿量降低了 12.4% 和 6.7%。由于环氧树脂的极性增加，1 wt% Fe ₂ O ₃纳米颗粒的添加使水分扩散系数降低了 11.7%，而由于环氧树脂的自由体积增加，0.25 wt% GONPs 使水分扩散系数增加了 38.5%。此外，与湿的纯环氧树脂相比，湿的 Fe ₂ O ₃ /环氧树脂纳米复合材料的强度和刚度分别提高了 28.8% 和 52.9%。与湿的纯环氧树脂相比，GONP/环氧树脂纳米复合材料的强度和刚度值最高分别高出 22.3% 和 13.4%。