In this article, short carbon fibers (CFs) reinforced rigid polyurethane (RPU) composites were prepared with the aim of improving both strength and toughness. A tannic acid (TA)‐nickel (Ni) composite coating was spontaneously co‐deposited onto CFs surface by a one‐step electrodeposition method to strengthen the interface bonding of the composites. The satisfactory mechanical properties of the composites were mainly attributed to the superior interfacial adhesion. On the one hand, TA could play a role in refining Ni grain during electrodeposition. On the other hand, the hydroxyl groups attached to composite coating, which were introduced by TA, could react with the RPU matrix to form chemical bonds. When the composites were under stress, the chemical bonds could effectively transfer the stress from matrix to the interface, while the refined Ni crystals could greatly increase the stress transfer path, and thus improve the strength and toughness of the material. Compared with pure RPU, the tensile strength, bending strength，interlaminar shear strength, and impact strength of TA‐Ni‐coated CFs/RPU composites were improved by 14.8%, 83.1%, 28.7%, and 121.4%, respectively.

中文翻译：

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碳纤维增强的硬质聚氨酯复合材料的强韧性，通过吸收单宁酸和细化碳纤维表面的镍晶粒

在本文中，制备了短碳纤维（CFs）增强的硬质聚氨酯（RPU）复合材料，旨在同时提高强度和韧性。通过一步电沉积方法将单宁酸（TA）-镍（Ni）复合涂层自发共沉积在CFs表面上，以增强复合材料的界面结合。复合材料令人满意的机械性能主要归因于优异的界面粘合性。一方面，TA可以在电沉积过程中起到细化镍晶粒的作用。另一方面，TA引入的附着在复合涂层上的羟基可与RPU基质反应形成化学键。当复合材料受到应力时，化学键可以有效地将应力从基体转移到界面，而精炼的镍晶体可以大大增加应力传递路径，从而提高材料的强度和韧性。与纯RPU相比，TA-Ni涂层CFs / RPU复合材料的拉伸强度，弯曲强度，层间剪切强度和冲击强度分别提高了14.8％，83.1％，28.7％和121.4％。