芳纶纤维表面光固化纳米复合涂层的制备及其对复合材料界面的增强机理研究

The super high strength, high modulus and high thermal stability of aramid fiber make it an ideal reinforcement additive for composites. Aramid fiber/polymer composites play an irreplaceable role in aerospace and bulletproof fields. However, due to the surface inertness, the adhesion between aramid and polymer matrix is seriously poor. Besides, the traditional surface coating technology faces the problems of environmental pollution, high energy consumption and low efficiency. In order to solve this problems, this work propose to use aramid nanofiber as the reinforcing agent, and take advantage of UV-curing technology to prepare nanocomposite coatings on the surface of aramid fibers. In the process of aramid fiber polymerization, through microstructural control to prepare aramid nanofiber with terminal methacrylate, which can take part in the UV-curing process. The aramid nanofiber can enhance the adhesion through improving the properties of coatings and connecting with aramid fiber via hydrogen bond and π-π stacking. Through studying the influence of UV-curing parameter on the aramid fiber interfacial adhesion to make sure the preparation rote. Through studying the influence of UV-curing nanocomposites coatings on the mechanical properties of fiber/polymer composites to explore the interface enhancement mechanism. This research will provide theoretical foundation for the green surface coating technology of aramid fiber, extend its application in polymer composites.

芳纶纤维具有超高强度、高模量、耐高温等特点，作为高性能复合材料的理想加强剂，在航空航天、防弹产品等领域具有不可替代的作用。然而，芳纶纤维表面呈现较大的化学惰性，与聚合物基体的界面粘结性能较差。本项目针对粘结性差以及传统表面涂层技术存在的污染环境、能耗高、效率低等问题，提出采用芳纶纳米纤维作为增强剂，利用紫外光固化技术在芳纶纤维表面制备纳米复合涂层，以得到环保、高效、界面粘结性好的表面涂层。在芳纶纤维聚合过程中，进行结构调控，制备端基带有甲基丙烯酸酯基的芳纶纳米纤维，使其能够参与光固化反应，通过增强表面涂层的性能以及通过氢键和π-π堆积作用与芳纶纤维建立连接，提高涂层的界面粘结性能；探索光固化条件对改性芳纶纤维性能的影响，确定表面涂层的制备路线；研究光固化纳米复合涂层对复合材料力学性能的影响，明确界面增强机理。本项目为芳纶纤维的绿色表面涂层技术及其复合材料的制备与应用提供了理论基础。

芳纶纤维具有超高强度、高模量、耐高温等特点，作为高性能复合材料的理想加强剂，在航空航天、防弹产品等领域具有不可替代的作用。然而，芳纶纤维表面呈现较大的化学惰性，与聚合物基体的界面粘结性能较差。本项目采用芳纶纳米纤维作为增强剂，制备了一系列光固化纳米复合涂层，研究了芳纶纳米纤维对光固化动力学的影响，并对涂层的结构、性能进行了深入研究。结果表明，芳纶纳米纤维的加入增强了光固化涂层的紫外屏蔽性能，并且力学性能也有较大提高。进一步使用不同改性剂对芳纶纳米纤维进行改性，制备得到了能够参与光固化反应的芳纶纳米纤维，研究结果表明，相比于未改性的芳纶纳米纤维，改性后的芳纶纳米纤维在聚合物基体中具有更好的分散性，力学性能也进一步提高。含有0.025 wt % 改性芳纶纳米纤维的纳米复合涂层与纯环氧丙烯酸酯涂层相比，断裂伸长率增加了446%。项目还进一步制备了环氧改性的芳纶纳米纤维，验证了脂环族环氧树脂基阳离子光固化涂料应用于芳纶纤维表面改性的可行性，为芳纶纤维的绿色表面涂层技术及其复合材料的制备与应用提供了理论基础。