微胶囊自修复聚合物材料的发展

对微胶囊自修复聚合物材料近年来一些新的研究进展进行了综述,包括微胶囊自修复聚合物材料技术的发展历程,荧光数字图像技术、光测弹性技术在微胶囊自修复聚合物材料研究领域的应用以及微胶囊／微血管自修复聚合物材料制备的技术要点。     

自修复聚合物材料用微胶囊的研究进展

介绍了微胶囊自修复聚合物材料的自修复机理,阐述了微胶囊的制备技术。讨论了近年来在该领域最新的研究成果,展望了微胶囊自修复复合材料的研究方向。     

微胶囊型自修复聚合物材料的研究进展

聚合物材料在使用过程中,内部不可避免地会产生裂纹。由于这些裂纹难以被检测和及时修复往往会缩短材料使用寿命。主要介绍微胶囊型自修复聚合物复合物材料的自修复机理,以及微胶囊、催化剂、修复剂等因素对材料自修复效率的影响。着重介绍该领域最新研究进展,并对微胶囊自修复聚合物复合材料的研究前景进行了展望。     

微胶囊型自修复涂料的研究进展

传统聚合物涂料在使用过程中因外界因素不可避免的产生划伤或裂纹,其保护性能就会大大降低,极大的缩短了聚合物涂料的使用寿命,增加了巨大的经济成本。经过国内外学者大量深入的研究,将自修复技术应用于复合涂料领域,即制备自修复聚合物涂料成为智能涂料发展的重要方向之一。本文根据自修复微胶囊外壳材料的不同,描述了几种常见的微胶囊型自修复涂料体系,包括脲醛树脂外壳体系、聚脲外壳体系、聚氨酯外壳体系等。     

微胶囊自修复技术及其在聚合物基复合材料中的应用

论述了微胶囊自修复技术以及自修复机理,重点阐述了微胶囊自修复技术在聚合物基复合材料中应用的最新研究成果.通过分析聚合物基自修复复合材料对微胶囊结构和性能的要求,指出了今后的发展方向和应用前景.     

沥青自愈合技术的研究进展与展望

从自愈合聚合物材料的主要愈合机理和沥青材料自愈合的方法两个角度介绍沥青材料自愈合技术的研究进展。高分子聚合物材料的愈合机理包括:基于微胶囊和液芯纤维的愈合方法;基于可逆共价键和非共价键的愈合机理;基于形状记忆材料以及纳米粒子的自修复机理等。简单介绍了沥青材料发生自愈合的理论基础。沥青材料的自愈合方法包括:微胶囊法;自愈合聚合物材料改性沥青;加热愈合方法。分析了沥青材料自愈合几种不同方法的优缺点,并对未来的研究方向做出了展望:微胶囊法属于聚合物材料愈合中初级的修复方法,属于被动修复且局限性较多。沥青自愈合的研究应着眼于促进或提高沥青自身的自愈合能力和提出新的加热促进愈合的方法。     

树脂基复合材料微胶囊自修复技术综述

微胶囊自修复技术通过在树脂中包埋胶囊来实现材料的快速损伤监测和起始损伤修复.本文综述了微胶囊修复技术中针对微胶囊形状和尺寸的参数优化方法.同时,综述了微胶囊在树脂基体中与裂纹作用的研究方法.分析了现有微胶囊自修复技术设计中存在的未考虑修复剂物理特性的问题.展望了未来微胶囊自修复技术与可视化材料监测及全局自修复材料技术相...     

异氰酸酯微胶囊研究进展

本文综述了异氰酸酯微胶囊在基体材料中的自修复机理,按照异氰酸酯微胶囊的芯材类型,从脂环族、脂肪族和芳香族三个方面介绍了使用不同聚合方法制备的不同囊壁(单层,双层和杂化层)的异氰酸酯微胶囊的覆盖率、渗透性、耐溶剂性和修复效率,并简要介绍了异氰酸酯微胶囊在聚合物防腐涂料、自清洁涂层、耐摩擦涂层、水处理膜及胶粘剂方面的应用,最后提出了现有异氰酸酯微胶囊存在的主要问题及未来的发展方向。     

自修复材料及在涂料中的应用

介绍了自修复技术,讨论了目前研究最多的微胶囊技术,包括材料的选择和制备、修复机理、研究进展及在涂料中的应用等.     

环氧树脂微胶囊的制备与性能研究

随着社会快速发展,人们对材料的安全性和耐久性越来越重视。复合材料在使用过程中,受到外界荷载、温度等环境作用,材料内部会产生微裂纹。将自修复材料微胶囊化,可修复材料微裂纹,改善材料耐久性,并提高复合材料使用寿命。本研究采用原位聚合法制备微胶囊,以尿素与甲醛作为壁材,环氧树脂E51为芯材制备,具有致密性较好,反应速率较快,且聚合物相对分子质量高等优点。在此基础上,本文系统地研究了合成工艺对环氧树脂微胶囊性能的影响。分析研究了微胶囊的形貌、化学结构、平均粒径,以及这些差异对微胶囊性能的影响。确定了影响微胶囊产率、芯材含量、抗渗透性、平均粒径的最大因素为反应时间。结果表明,制备的微胶囊为球形,粘性小,且成功将环氧树脂包覆在微胶囊中。测定最佳条件下微胶囊的产率和芯材含量分别为64.9%和69.6%。     

界面聚合技术及其应用研究进展

介绍了界面聚合技术的基本原理、界面缩合反应的类型,综述了国内外近年来界面聚合技术在膜材料（高聚物膜材料和无机膜材料）、微胶囊材料（农药微胶囊、阻燃微胶囊、微胶囊相变材料和智能型微胶囊材料）、新型纤维粒子及新型材料（聚苯胺粒子、聚次甲基吡咯导电微球、聚二甲基硅氧烷等）中的应用研究进展。     

Effect of microcapsule size on the performance of self-healing polymers

The influence of microcapsule diameter and crack size on the performance of self-healing materials is investigated. These epoxy-based materials contain embedded Grubbs' catalyst particles and microencapsulated dicyclopentadiene (DCPD). Autonomic repair is triggered by rupture of the microcapsules in response to damage, followed by release of DCPD into the crack plane where it mixes with the catalyst and polymerizes. The amount of liquid that microcapsules deliver to a crack face is shown to scale linearly with microcapsule diameter for a given weight fraction of capsules. In addition, self-healing performance reaches maximum levels only when sufficient healing agent is available to entirely fill the crack. Based on these relationships, the size and weight fraction of microcapsules can be rationally chosen to give optimal healing of a predetermined crack size. By using this strategy, self-healing is demonstrated with smaller microcapsules and with lower weight fractions of microcapsules than have been possible in previous self-healing systems.     

Preparation and characterization of controlled-release microencapsulated acids for deep acidizing of carbonate reservoirs

Based on the deficiency of traditional acidification or acid pressure technology in the development of carbonate oil and gas resources, a microcapsule which wraps hydrochloric acid and can be released through temperature control was prepared by using microcapsule technology. The microcapsules were prepared with polyurethane prepolymer (PUA) and 1,6-hexadiol diacrylate (HDDA) polymer as wall material and hydrochloric acid as core material by two emulsification and photocatalysis methods. Its parcel rate is 61.9%. Fourier transform infrared spectroscopy characterization confirmed the successful photopolymerization of PUA prepolymer and HDDA in a strong acid environment. The microscopic morphology analysis of electron microscope showed that the microcapsule was regular and uniform spherical with smooth and dense surface. The particle size analysis showed that the microcapsules were mainly distributed between 40 and 300 μm, and the average particle size was 114.02 μm.The glass temperature of microcapsule wall material was 97°C by DSC method. The release rate of microcapsules was accelerated with the increase of release temperature. The cumulative release rate of acid solution of microcapsules for 3 h reached 28.4%, and the final release rate of microcapsules for 12 h reached 90.7% under 100°C. In addition, the release of microcapsules is less affected by the formation salinity. At 90°C, the maximum release rate of 7.5 g/L CaCL₂ was 49.1%, lower than that of 59.4% in pure water, showing the good salt resistance of the wall materials of microcapsules.     

自修复聚合物材料用微胶囊

Microcapsules with dicyclopentadiene (DCPD) as core material and urea formaldehyde resin as wall material used for making self-healing polymer material were prepared with the in-situ polymerization method. The effect of microcapsules on the fracture toughness of epoxy resin was studied. The addition of microcapsules into epoxy resin results in the decrease of fracture toughness. When microcapsule content was kept constant, as the microcapsule size increased the fracture toughness of the epoxy resin decreased linearly and the percentage of decrease compared to the neat epoxy without microcapsules increased linearly. Moreover, the fracture toughness of the material decreases linearly with the increase of microcapsule content.     

自修复聚脲甲醛微胶囊的制备及成囊机理研究

采用原位聚合法制备了自修复聚脲甲醛包覆环氧树脂微胶囊。考察了原料用量、反应温度、酸化值和固化时间等对微胶囊粒径分布和表面形态的影响,确定了微胶囊的最佳制备工艺。借助显微镜实时监测微胶囊化过程,探讨了微胶囊的成囊机理,并将微胶囊填充到脲醛树脂中。结果表明:采用最佳制备工艺制得的微胶囊包覆率较高、结构紧密、粒度均匀,室温下保存一周后没有出现团聚和破裂;将9%微胶囊添加到脲醛树脂中,微胶囊分散均匀,脲醛树脂复合材料的韧性得到提高。     

Tribological and mechanical properties of PBT composites with microcapsules and potassium titanate whiskers

Melamine resin microcapsules encapsulating liquid paraffin as core materials are synthesized. By using melt blending method, different ratios of microcapsules and modified potassium titanate whiskers (PTWs) are added to poly(butylene terephthalate) (PBT) matrix to fabricate the binary and ternary PBT composites. The effect of oil‐loaded microcapsules content on mechanical properties and tribological properties of PBT composites are evaluated by electronic universal testing machine and high speed block‐on‐ring wear tester, respectively. The results indicate that the incorporation of microcapsule could significantly reduce the friction and wear of the composites mainly due to the self‐lubricating effect of liquid paraffin released from the ruptured microcapsule during the friction process; however, the mechanical properties of the PBT binary composites are reduced. Hence, PTWs are adopted to effectively improve the mechanical properties of materials which could improve the tribological properties of the ternary composites as well due to the synergistic effects of microcapsules and PTWs. POLYM. ENG. SCI., 59:490–499, 2019. © 2018 Society of Plastics Engineers     

水泥基用相变微胶囊的颗粒特征与热力学性能

以石蜡、癸酸为芯材,脲醛树脂为壁材,间苯二酚为固化剂,采用原位聚合法制备相变微胶囊,采用ESEM、DSC、TGA来研究相变微胶囊颗粒形貌、粒径分布、热力学性能,以及相变微胶囊掺入水泥基体中的微观形貌.结果表明:微胶囊表面光滑,结构紧致;石蜡微胶囊的相变温度和相变焓分别是54.6℃和61.43 J/g,而癸酸微胶囊的相.变温度和相变焓分别是29.7℃和90.73 J/g;加入固化剂使得微胶囊产率从50％提升到78％以上;30次温度循环石蜡微胶囊相变晗无损失,癸酸微胶囊相变焓损失了31％;微胶囊在水泥基中分布均匀,形貌保存良好.     

基于六官能度异氰酸酯用于自修复防腐涂料的微胶囊的制备与表征

微胶囊自修复技术是将自修复微胶囊埋植于基体,在破坏后实现自我修复。IPDI作为低官能度异氰酸酯在湿气中固化修复能力有限,本文设计基于六官能度异氰酸酯DiPE-IPDI/DiPE-TDI合成用于自修复防腐涂料的新型微胶囊,着重对六官能度异氰酸酯DiPE-IPDI合成过程中溶剂、温度进行反应条件优化,通过傅里叶红外光谱、核磁等对产物结构进行表征。同时对微胶囊制备过程中粒径结构进行可控组装, 通过TGA/DSC表征该自修复微胶囊热力学性能。制备负载微胶囊的自修复环氧树脂基防腐涂料,盐雾试验结果显示其具有优异的自修复性能。     

Influence of microcapsule shell material on the mechanical behavior of epoxy composites for self‐healing applications

In this article, we have studied the effect of microcapsule shell material on the mechanical behavior of self‐healing epoxy composites. Liquid epoxy healant was encapsulated in melamine‐formaldehyde (MF) and urea‐formaldehyde (UF), using emulsion polymerization technique to prepare microcapsules of different shell walls. The core content of the microcapsules, as determined by solvent extraction technique was found to be 65 ± 4%, irrespective of the shell wall of microcapsule. Morphological investigations reveal a rough texture of the spherical microcapsules, which was attributed to the presence of protruding polymer nanoparticles on the surface. Epoxy composites containing UF and MF microcapsules (3–15% w/w) were prepared by room temperature curing and their mechanical behaviour was studied under both quasi‐static and dynamic loadings. The tensile strength, modulus, and impact resistance of the matrix was found to decrease with increasing amount of microcapsule in the formulation, irrespective of the shell wall material used for encapsulation. Interestingly, substantial improvement in the fracture toughness of the base resin was observed. Morphological investigations on the cracked surface revealed features like crack pinning, crack bowing, microcracking and crack path deflection, which were used to explain the toughened nature of microcapsule containing epoxy composites. Our studies clearly indicate that the microcapsule shell wall material does not play any significant role in defining the mechanical properties of the composites. In addition, presence of secondary amine functionalities in UF and MF shell wall do not interfere with the reaction of epoxy with triethylene tetramine hardener during the curing process. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40572.     

The effect of synthesis condition on physical properties of epoxy‐containing microcapsules

The physical properties of microcapsules are largely influenced by the synthesis conditions such as weight ratio of core/shell material, agitation rate, reaction time, and different emulsifier. Different synthesis condition would lead to different property. It is an important issue for application in composites that require self‐healing microcapsules possessing rough surface morphology, less adhesion, less core material permeability, appropriate diameter and core content, and adequate shell thickness. The properties of microcapsules influenced by the synthesis conditions were investigated systematically in this article. According to orthographic factorial design, the most influencing factor on microcapsule's yield, core material, average shell thickness and average diameter, are concluded, respectively. The synthesis parameters when the epoxy‐containing microcapsules exhibit the optimum properties are concluded: 1.4 : 1 for the weight ratio of core/shell material, 250 rpm for the agitation rate, 3 h for the reaction time and 1.5% content for the emulsifier DBS. The chemical structure of resultant microcapsules is confirmed by FT‐IR, and core material of microcapsule exhibits reactivity through DSC measurement. Subsequently, the microcapsules are characterized by SEM, OM, and contact angle experiment so as to provide parameters of microcapsule's physical properties for making binary self‐healing materials. As a result, the resultant microcapsules are suitable for fabricating self‐healing materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012