自愈合水凝胶的研究进展

自愈合水凝胶作为一种新型功能凝胶材料，目前在现代科学研究中展现了十分突出的应用前景。本文对水凝胶的自愈合机理进行了描述和分类。非共价交联水凝胶与共价交联水凝胶都有着不同的自愈合性质。非共价交联水凝胶主要以氢键、疏水相互作用以及离子键来实现其自愈合的性质，而共价交联水凝胶的自愈性主要依靠动态共价键以及金属配位键。本文还描述了近些年来自愈合水凝胶在生物医疗、3D打印、可穿戴电子产品以及离子吸附的部分应用。最后，对自愈合水凝胶未来的发展作了展望。     

自愈合聚氨酯材料的研究进展

综述了近年来本征型和埋植型2种自愈合聚氨酯体系的研究进展与成果;探讨了不同自愈合类型的愈合机理及效果,并对自愈合聚氨酯材料未来的发展进行了展望.     

分子量不同的软段对自愈合聚氨酯弹性体性能的影响

用两种不同分子量的聚丙二醇分别制备了具有自愈合功能的聚氨酯弹性体，研究了它们的力学性能和自愈合性能，讨论了愈合温度和愈合时间对自愈合性能的影响。结果表明，两种聚氨酯材料在断裂后均有良好的自愈合功能，断裂后的聚氨酯（PPG 1000）在40 ℃下6 h的拉伸强度和扯断伸长率能分别恢复到2.58 MPa和500 %，愈合效率为30 %，而原始拉伸强度并不高的聚氨酯（PPG 2000）可分别达到1.25 MPa和1 000%，愈合效率高达94 %。聚氨酯材料的自愈合性能并非完全由氢键强度决定，而是受到氢键强度和软段结构共同的影响。延长愈合时间和提高愈合温度均能提高愈合效率。该类材料在室温条件下就可达到较好的愈合效果，这有望在户外防护领域得到应用。     

聚氨酯自愈合材料的研究进展

聚氨酯自愈合材料是可以进行自我修复以恢复力学性能的一种功能聚氨酯材料。主要介绍了Diels-Alder化学方法、超分子化学方法、微胶囊化方法和光化学方法制备聚氨酯自愈合材料的研究进展。     

基于超分子相互作用的自愈合聚氨酯材料

聚氨酯材料由于其固有的氢键结构被认为是一种理想的自愈合材料。将超分子化学体系引入到聚氨酯中,可以获得性能更加出色的自愈合材料。这些基于超分子相互作用的自愈合聚氨酯材料在受损后能够恢复其大部分物理和化学性质,具有优异的性能。该文首先从不同类型的愈合机理出发,综述了近年来基于超分子相互作用的自愈合聚氨酯材料,包括氢键结合体系、基于芳香基的π-π堆积体系、链段侧链中含有离子基团并彼此形成交联点的离子交联聚合物体系、金属离子与配体进行配位引起材料交联的金属配体相互作用体系、大环分子与特定大小的分子形成包合物的主客互动体系。然后展望了自愈合聚氨酯未来发展优势。     

本征型自修复聚氨酯材料的研究进展

综述了通过引入可逆Diels-Alder键和可逆共价双硫键的热引发和利用紫外线、红外线的光引发实现本征型自修复聚氨酯（PU）材料的研究进展;探讨了本征自修复的修复机理,并对自修复PU材料的发展方向进行了展望。     

自修复聚氨酯材料功能化的研究进展

综述了自修复聚氨酯材料功能化研究进展，重点介绍了自修复导电聚氨酯材料、自修复导热聚氨酯材料、自修复抗菌聚氨酯材料、自修复阻燃聚氨酯材料、自修复可回收聚氨酯材料等，并对其应用做了简要阐述。     

吏用创新型聚氨酯材料与加工技术实现表面升级

本文介绍了一种创新型聚氨酯材料体系（puroclear），包括其在汽车行业的表面升级应用和相应加工技术（CCM、ColorForm和表面RTM技术）。puroclear材料是基于脂肪族多异氰酸酯的高光泽度和自愈合型聚氨酯表面涂层，通过使用上述加工技术，puroclear材料可以在相对温和的加工温度下快速应用于各种基村材料的表面，     

聚氨酯-丙烯酸酯纳米TiO_2交联共聚物的制备和性能研究

本试验使表面接枝有聚丙烯酰氯的纳米TiO2与端基聚氨酯发生酯化反应,实现了聚氨酯对TiO2纳米材料的表面共价接枝。然后通过透射电子显微镜研究了纳米TiO2在基体中的分散。并对材料进行了力学、光学和热学性能的研究,通过了DSC、FTIR表征。通过这些测试证明此材料接枝成功以及材料具有更好的性能。     

一种自修复聚氨酯的制备及表征

采用两种高柔性聚醚多元醇PPG1000和PPG2000,通过脂环族二元胺(IPDA)扩链制得两种聚氨酯弹性体:聚氨酯-PPG1000和聚氨酯-PPG2000,并通过示差扫描量热分析、动态热力学分析、凝胶渗透色谱及拉伸性能测试对其结构和性能进行了研究。结果表明:合成的两种聚氨酯弹性体的分子质量约为9万,聚氨酯-PPG1000的玻璃化转变温度为-31℃,聚氨酯-PPG2000为-53℃。它们在室温下均具有较好的弹性,两种聚合物在40℃下愈合3 h即可完成自修复,室温下24 h同样可以达到良好的自愈合效果。聚氨酯-PPG2000的修复效率远高于聚氨酯-PPG1000,这与材料中软段含量有直接关系。该成果有望在户外防护领域得到应用。     

基于可逆共价键自修复聚氨酯的研究进展

聚氨酯作为一种新兴的有机高分子材料,被誉为"第五大塑料",以其优异的综合性能而广泛应用于轻工、建筑、汽车、航空和航天等领域.但是,其在加工或使用过程中,难免因外力作用而发生结构破坏,从而极大地降低了材料的力学性能和产品的使用寿命.可逆共价键是一种能够在一定条件下实现可逆断裂与重组的动态共价键.因此,将其引入聚氨酯分子链...     

本征型自修复聚合物材料研究进展

回顾了自修复聚合物材料的研究现状,目前所采用的自修复方法主要包括外援型自修复（纳米粒子自修复、微胶囊自修复、空心纤维自身修复、微脉管自修复等）和本征型自修复（可逆共价键自修复、可逆非共价键自修复）,重点介绍了本征型自修复聚合物材料的最新研究进展,可逆共价键自修复是通过在体系中引入酰腙键、双硫键、N-O键、Dieal-Alder可逆反应等实现的,可逆非共价键自修复是借助于体系中的氢键作用、疏水作用、静电作用、离子作用、大分子扩散作用、金属配体作用等机理实现的,对它们的修复机理及研究现状进行了系统的阐述,展望了自修复材料潜在的应用领域,如高屋建筑、核材料贮存、生物医疗材料等。     

Self-healing polyurethane based on a substance supplement and dynamic chemistry: Repair mechanisms and applications

This review systematically summarizes the repair mechanisms and applications of self-healing polyurethane (SHPU) materials aiming at energy conservation and safety under different repair methods. As of now, the repair methods that have emerged can be divided into two categories: substance landfill and bond repair. In terms of the repair mechanisms for both, the former involves the release of healing agents from micro-carriers (microcapsules, hollow fibers, and microvascular) to fill the damaged area upon external impact. In contrast, bond repair combines physical and chemical changes triggered by light, heat, and other factors. To achieve efficient self-healing in this mode, both the reorganization of broken chemical bonds and the high mobility of chain segments are crucial. Reversible covalent bonds and supramolecular interactions, as two branches of aforementioned reversible chemical bonds, share the responsibility for maintaining efficient self-healing despite infinite cycling. Additionally, multiple synergistic crosslinked networks, special nanomaterials, and microphase separation are often used to solve the problem of incompatible healing efficiency and mechanical strength in bond repair. When the perspective is focused on the application, this gradually improved SHPU with strong potential and comprehensive performance has provided raw materials for many fields related to human development, such as road, architecture, healthcare, and electronic.     

Polyurethane toughened covalent adaptive networks epoxy composite based on thermoreversible Diels-Alder reaction: Self-healable,shape memory,and recyclable

Covalent adaptive networks (CANs) epoxy based on the Diels-Alder (DA) reaction usually are commonly used for self-healing materials. However, poor toughness greatly limits its application in innovative materials. Herein, based on retaining the excellent dynamic characteristics of DA reactive CANs, we introduced thermoplastic polyurethane (TPU) in situ during crosslinking, improving the composite material's strength and toughness. A multicomponent polymeric system with advanced performance can be produced by the individual components on the condition of the synergistic hybrid effects. Molecular-level interlocking polymer networks between the chain entanglement of TPU and the reversible covalent crosslink of DFB were formed by the topological reorganization of these two immiscible polymers. As the gelation proceeds, a homogenous structure instead of conventional phase separation is formed. When the mixing ratio of DFB and TPU is 1:1, the tensile strength of the prepared sample reaches 35 MPa, and the elongation at break reaches 110%. At the same time, the composites possess good thermal stability and solvent resistance due to the presence of interlocking polymer networks. Furthermore, these DFB-TPU composites show excellent shape memory, self-healing, and closed-loop recycling properties.     

Tough,self-healing,and recyclable cross-linked polyurethane elastomers via synergistic effect of dual dynamic covalent bonds

Based on the irresistible inherent trade-off between the mechanical and self-healing performances of cross-linked polyurethane materials, there is still an intractable challenge to design efficient self-healing and tough elastomers, especially in flexible sensors. Herein, a tough, efficient self-healing, and recyclable cross-linked polyurethane elastomer (DTPU) was prepared by integrating oxime-carbamate bonds and thiourethane bonds into the network. The extraordinary mechanical properties and self-healing performances of DTPU elastomers were related to the synergistic effect of oxime-carbamate bonds in the main chain and thiourethane bonds in the chemical cross-linked sites. The existence of dynamic cross-linked points not only optimized the mechanical properties of DTPU but also provided support for the reversible cleavage and formation of oxime carbamate bond, thus endowing DTPU with efficient self-healing performance and recyclability. After self-healing at mild temperatures for 6 h, the self-healed DTPU elastomers had a tensile strength of 30.27 MPa and a self-healing efficiency of 95.5%. After multiple hot-pressing, the original mechanical strength of DTPU was restored to over 100%, exhibiting excellent recyclable characteristics. Additionally, strain sensors based on self-healing flexible elastomers were fabricated by introducing conductive carbon nanotubes. The strain sensors maintained their electrical conductivity after 3 times self-healing, demonstrating great potential in healable flexible electronics.     

Synthesis of Diels–Alder bond and hydrogen bond synergistic shape memory self-healing polyurethane elastomers

Self-healing materials exhibit the ability to repair damage and restore their function. Shape memory assisted self-healing (SMASH) materials are smart materials that automatically close localized microscopic cracks and repair these cracks by bonding damaged surfaces. A novel temperature-responsive SMASH polymer composite was established by introducing Diels–Alder bonds (D–A) in polyurethane. In this article, dynamic D–A produced by the polymerization of furfurylamine and 4,4’-bismaleimidodiphenylmethane was introduced into the molecular chain to enable the polyurethane elastomers containing D–A bonds to acquire self-repairing capability. The self-healing properties of the synthesized material were examined using polarized light microscopy, which revealed excellent fracture healing. The mechanical properties before and after healing were tested, in which the initial maximum tensile strength of the material could reach 7.9 MPa, and the maximum tensile strength after self-healing was 7.3 MPa, with a repair rate of 91.8%; the maximum elongation was 585.9%, and the maximum elongation after self-healing was 469.5%, with a repair rate of 80.1%. In addition, this material has excellent repair performance for microcracks of different scales, and the micromolten part of the surface after heating can fill the micrometer cracks, play the role of antiaging, and extend the service life of the material.     

Multi-functional polyurethane composites with self-healing and shape memory properties enhanced by graphene oxide

Development of shape memory polymer materials with integrated self-healing ability, shape memory property, and outstanding mechanical properties is a challenge. Herein, isophorone diisocyanate, polytetramethylene ether glycol, dimethylglyoxime, and glycerol have been used to preparation polyurethane by reacting at 80°C for 6 h. Then, graphene oxide (GO) was added and the reaction keep at 80°C for 4 h to obtain polyurethane/GO composite with self-healing and shape memory properties. Scanning electron microscopy shows that the GO sheets were dispersed uniformly in the polyurethane matrix. The thermal stability was characterized by thermogravimetric analyses. The tensile test shows that the Young's modulus of the composites increases from 38.57 ± 4.35 MPa for pure polyurethane to 95.36 ± 10.35 MPa for the polyurethane composite with a GO content of 0.5 wt%, and the tensile strength increases from 6.28 ± 0.67 to 15.65 ± 1.54 MPa. The oxime carbamate bond and hydrogen bond endow the composite good self-healing property. The healing efficiency can reach 98.84%. In addition, the composite has excellent shape memory property, with a shape recovery ratio of 88.6% and a shape fixation ratio of 55.2%. This work provides a promising way to fabricate stimulus-responsive composite with versatile functions.     

Effect of chain extender on microphase structure and performance of self-healing polyurethane and poly(urethane-urea)

In this work, four aliphatic chain extenders, hexanediol (HDO), hexane diamine (HDA), cystamine (CY), and cystine dimethyl ester (CDE), were chosen to synthesize four kinds of polyurethane and poly(urethane-urea)s (PUs), respectively. HDO extended polyurethanes, HDA extended poly(urethane-urea), CY extended poly(urethane-urea), and CDE extended poly(urethane-urea) were denoted as OPU, APU, CPU, and SPU, respectively. The effect of chain extender type on microphase structure and performance of four PUs was investigated. Our research showed that mechanical strength increased in the following order: OPU < SPU < CPU < APU, and self-healing performance increased in the opposite direction. This result is attributed to the increasing degree of microphase separation: OPU < SPU < CPU < APU. The optimal sample SPU has not only excellent mechanical properties (tensile strength of 27.1 MPa and elongation at break of 397.7%), but also exhibits superior self-healing performance (self-healing efficiencies of 95.3% and 93.5% based on tensile strength and elongation at break). The moderate degree of microphase separation between the soft segments and the hard segments, the introduction of disulfide bonds and low degree of hydrogen bonding are responsible for preparing a polyurethane or poly(urethane-urea) system with high mechanical strength and excellent self-healing performance simultaneously. This work provides useful information for us to develop self-healing polyurethane or poly(urethane-urea) materials in the future.     

水性聚氨酯防腐涂料改性的最新研究进展

腐蚀已经成为危害世界经济，构成重大事故的罪魁祸首之一，因此如何解决腐蚀的问题是我们目前必须要攻克的难关。水性聚氨酯涂料作为一种防腐材料，无毒无味，安全环保，但防腐性能依然需要提高，为了进一步提高产品的防腐性能，研究人员使用不同改性方法制备功能各异的水性聚氨酯防腐涂料。本文主要介绍了通过纳米材料、自修复等几种较常用的改性方法对水性聚氨酯涂料改性，并对未来的研究方向和发展趋势进行了展望。     

自修复超疏水材料的制备及功能化研究进展

该文归纳了近年来自修复超疏水材料的研究进展,总结了外援型和本征型自修复超疏水材料的制备方法,并介绍了功能化自修复超疏水材料及其应用,最后指出了自修复超疏水材料现阶段所面临的挑战和未来的发展方向。与普通超疏水材料相比,自修复超疏水材料具有优良的表面稳定性和循环使用性,其使用寿命得到明显延长。此外,将自修复超疏水材料功能化,还能够进一步扩大其使用范围。随着科学技术的发展,自修复超疏水材料必将在电子电器、医疗卫生、人工智能、海水淡化等众多领域中发挥关键性作用。