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形状记忆聚氨酯复合微胶囊的协同自修复机制研究
樊伟杰
Subtype博士
Thesis Advisor李伟华
2019-05-17
Degree Grantor中国科学院大学
Place of Conferral中国科学院海洋研究所
Degree Discipline海洋腐蚀与防护
Keyword形状记忆 微胶囊 靶向 协同自修复
Abstract

涂料因施工简单、成本较低、效果优异、易于维护等优点广泛用于海洋工程的防腐。海洋工程装备服役过程受外部环境和作业过程中机械作用影响,表面涂层不可避免地会受到损伤,若不及时修复则会使金属基材和部分非金属零部件发生腐蚀,影响结构强度和可靠性,不仅会造成巨大的经济损失,甚至导致灾难性事故的发生。涂装有自修复功能的防腐涂料是解决这一问题的有效途径。目前,针对涂层自修复技术的研究有很多,但由于受修复机制和作用原理的限制,单一修复技术应用于涂层自修复时,通常会有一定的局限性,一定程度上限制了自修复涂料的修复效果和实际修复效果。本论文综合采用微胶囊修复技术和形状记忆修复技术的优势,借助其响应触发机理不同的原理,通过技术手段实现两种不同机制间的有效协同作用,实现对多种尺寸涂层裂纹的修复。主要开展以下研究:
(1)研究采用溶液聚合法制备用于涂层自修复的微胶囊方法;通过调控囊芯/囊壁的选材及合成工艺参数,实现微胶囊尺寸的控制和工艺优化;在此基础上,借助化学接支和物理共混的方式探究改性技术,实现分别针对热场、磁场、电场、H+等不同因素的动力驱动剂,使微胶囊具备靶向作用特性。综合考虑芯壁质量比、乳化剂种类、乳化剂质量分数及酸化时间等因素对形成的微胶囊的包覆率、平均粒径等性能影响的基础上采用最优配方进行合成。研究结果表明,当芯壁质量比(2:1)、乳化剂种类及质量分数分别是 0.8 %的阿拉伯胶、搅拌速率为 1500 r/min 时,制备的微胶囊分散性较好,粒径较小,囊壁较薄,且微胶囊表面粗糙,利于在基体中分散。微胶囊的热稳定性能较好。
(2)采用乳液聚合法合成具有形状记忆特性的聚氨酯成膜物;根据实际服役环境,分别选择不同的软段/硬段和交联剂等单体,通过调控软硬段含量及制备工艺参数实现适合不同环境的形状记忆成膜物;借助红外光谱、失重分析、形状记忆性能、核磁共振谱等,研究了硬段含量对形状记忆聚氨酯结构与性能的影响。研究发现线型形状记忆聚氨酯以软段的“结晶-熔融”相转变为形状记忆机理的。所以,软段在室温条件下具有良好的结晶性是其具有形状记忆功能的必要条件一,硬段含量为 30~40%时形成的硬段微区,能够有效起到物理交联点的作用。通过红外光谱、固含量测定、形状记忆性能等一系列表征手段对合成的形状记忆聚氨酯进行性能表征,试验结果表明当硬段含量为 30~40%时,形状记忆性能及各项性能最佳。深层次揭示了形状记忆成膜物的设计思路和合成方法。
(3)通过物理共混的方式将靶向修复微胶囊与形状记忆成膜物进行负载,以此为主体搭配其他颜填料制备自修复智能涂料,利用不同修复技术的触发因素差异特点,实现不同修复技术的有序表达、协同修复和优势互补,分别提出“先钝化-后回复”和“钝化同时回复”两种协同自修复机制; 同时从物理修复和化学修复两种角度实现对大尺寸划痕的修复,使得整体修复率可达 85%以上,并解决修复后涂层与基体结合力不强的问题;引入感应自加热和特定因素响应机制,拓展了自修复涂层适用环境范围。,在实验室测试和外场暴露试验中均性能较为优异,具有一定推广应用价值,为后续高性能智能自修复涂层的发展提供理论基础。

Other Abstract

The coating is widely used in marine engineering for corrosion prevention due to its simple construction, low cost, excellent effect and easy maintenance. The serviceprocess of offshore engineering equipment is affected by the external environment and the mechanical action during the operation process. The surface coating will inevitably be damaged. If it is not repaired in time, the metal substrate and some non-metallic parts will be corroded, which will affect the structural strength and reliability. Sex, not only will cause huge economic losses, but even lead to catastrophic accidents. Anti-corrosion coatings coated with self-healing are an effective way to solve this problem. At present, there are many researches on self-repair technology of coatings. However, due to the limitation of repair mechanism and principle of action, single repair technology is usually applied to self-repair of coatings, which usually has certain limitations, which limits self-repair to some extent. The repair effect of the paint and the actual repair effect. This paper comprehensively adopts the advantages of microcapsule repair technology and shape memory repair technology. With the principle of different response trigger mechanism, the effective synergy between two different mechanisms is realized by technical means to realize the repair of cracks of various sizes. Mainly carry out the following research:
(1) Study on the preparation of microcapsules for coating self-repair by solution polymerization; control the size and process optimization of microcapsules by adjusting the material selection and synthesis process parameters of the core/sac wall; on this basis, by means of chemistry The method of coupling and physical blending explores the modification technology to realize the dynamic driving agent for different factors such as thermal field, magnetic field, electric field and H+, so that the microcapsule has the targeting function. Considering the factors such as the mass ratio of core wall, the type of emulsifier, the mass fraction of emulsifier and the acidification time, the optimal formulation was used to synthesize the influence of the coating rate and average particle size of the formed microcapsules. The results show that when the core wall mass ratio (2:1), the emulsifier type and the mass fraction are 0.8% of gum arabic and the stirring rate is 1500 r/min, the prepared microcapsules have better dispersibility and particle size. Small, the wall of the capsule is thin, and the surface of the microcapsule is rough, which is favorable for dispersion in the matrix. The thermal stability of the microcapsules is good.
(2) The polyurethane film-forming materials with shape memory properties were synthesized by emulsion polymerization; according to the actual service environment, different soft segments/hard segments and cross-linking monomers were selected, and the soft and hard segment content and preparation process parameters were adjusted.
The shape memory film suitable for different environments was realized. The effects of hard segment content on the structure and properties of shape memory polyurethane were studied by means of infrared spectroscopy, weight loss analysis, shape memory performance and nuclear magnetic resonance spectroscopy. It has been found that linear shape memory polyurethane transforms into a shape memory mechanism in the "crystal-melt" phase of the soft segment. Therefore, the soft segment has good crystallinity at room temperature, which is one of the necessary conditions for shape memory function. The hard segment microdomain formed when the hard segment content is 30~40% can effectively reach the physical cross-linking point. effect. The properties of the synthesized shape memory polyurethane were characterized by infrared spectroscopy, solid content determination and shape memory properties. The experimental results show that the shape memory performance and performance are best when the hard segment content is 30~40%. Deeply reveals the design ideas and synthetic methods of shape memory film formation.
(3) The target repair microcapsules and the shape memory film-forming materials are loaded by physical blending, thereby preparing self-repairing smart paints with other pigments and fillers, and different triggering factors of different repair technologies are used to realize different The orderly expression, synergistic repair and complementary complementarity of the repair technology respectively propose two synergistic self-repair mechanisms: “first passivation-post-recovery” and
“passivation simultaneous reply”; at the same time, from the two aspects of physical repair and chemical repair The repair of the size scratches can make the overall repair rate reach more than 85%, and solve the problem that the adhesion between the coating and the substrate is not strong after the repair; the induction self-heating and the specific factor response mechanism are introduced, and the applicable environmental range of the self-repair coating is expanded. . In the laboratory test and the field exposure test, the performance is superior, and it has certain promotion and application value, which provides a theoretical basis for the development of the subsequent high-performance intelligent self-healing coating.

Language中文
Document Type学位论文
Identifierhttp://ir.qdio.ac.cn/handle/337002/156828
Collection海洋环境腐蚀与与生物污损重点实验室
Recommended Citation
GB/T 7714
樊伟杰. 形状记忆聚氨酯复合微胶囊的协同自修复机制研究[D]. 中国科学院海洋研究所. 中国科学院大学,2019.
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