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Abstract：
In recent years, self-healing polymers have emerged as a topic of considerable interest owing to their capability to partially restore material properties and thereby extend the product\'s lifespan. The main purpose of this study is to investigate the nanoindentation response in terms of hardness, reduced modulus, contact depth, and coefficient of friction of a self-healing resin developed for use in aeronautical and aerospace contexts. To achieve this, the bifunctional epoxy precursor underwent tailored functionalization to improve its toughness, facilitating effective compatibilization with a rubber phase dispersed within the host epoxy resin. This approach aimed to highlight the significant impact of the quantity and distribution of rubber domains within the resin on enhancing its mechanical properties. The main results are that pure resin (EP sample) exhibits a higher hardness (about 36.7% more) and reduced modulus (about 7% more), consequently leading to a lower contact depth and coefficient of friction (11.4% less) compared to other formulations that, conversely, are well-suited for preserving damage from mechanical stresses due to their capabilities in absorbing mechanical energy. Furthermore, finite element method (FEM) simulations of the nanoindentation process were conducted. The numerical results were meticulously compared with experimental data, demonstrating good agreement. The simulation study confirms that the EP sample with higher hardness and reduced modulus shows less penetration depth under the same applied load with respect to the other analyzed samples. Values of 877 nm (close to the experimental result of 876.1 nm) and 1010 nm (close to the experimental result of 1008.8 nm) were calculated for EP and the toughened self-healing sample (EP-R-160-T), respectively. The numerical results of the hardness provide a value of 0.42 GPa and 0.32 GPa for EP and EP-R-160-T, respectively, which match the experimental data of 0.41 GPa and 0.30 GPa. This validation of the FEM model underscores its efficacy in predicting the mechanical behavior of nanocomposite materials under nanoindentation. The proposed investigation aims to contribute knowledge and optimization tips about self-healing resins.
摘要：
近年来,自修复聚合物已经成为一个相当感兴趣的话题，因为它们能够部分恢复材料性能，从而延长产品的使用寿命。这项研究的主要目的是研究硬度方面的纳米压痕响应，降低模量，接触深度,和摩擦系数的自修复树脂开发用于航空和航空航天环境。为了实现这一点，双官能环氧前体经过定制的官能化，以提高其韧性，促进与分散在主体环氧树脂内的橡胶相的有效相容。该方法旨在强调树脂内橡胶域的数量和分布对增强其机械性能的显著影响。主要结果是纯树脂（EP样品）表现出更高的硬度（约36.7％以上）和降低的模量（约7％以上），因此，与其他配方相比，导致较低的接触深度和摩擦系数（减少11.4％）相反,由于其吸收机械能的能力，非常适合于保持机械应力的损坏。此外，对纳米压痕过程进行了有限元模拟。将数值结果与实验数据进行了细致的比较，显示良好的协议。模拟研究证实,相对于其他分析样品,具有较高硬度和降低的模量的EP样品在相同的施加载荷下显示较小的穿透深度。计算了EP和增韧自愈样品（EP-R-160-T）的877nm（接近876.1nm的实验结果）和1010nm（接近1008.8nm的实验结果）的值，分别。硬度的数值结果为EP和EP-R-160-T提供了0.42GPa和0.32GPa，分别,与0.41GPa和0.30GPa的实验数据相匹配。FEM模型的验证强调了其在预测纳米压痕下纳米复合材料的力学行为方面的功效。拟议的调查旨在提供有关自修复树脂的知识和优化技巧。
